TY - JOUR
AU - Rocco, Richard, M
AB - Abstract The year 2006 marks the 50th anniversary of the discovery of cellulose acetate (CA) electrophoresis by Joachim Kohn, a pathologist at Queen Mary’s Hospital in Roehampton, London. During a career in pathology that began in 1950 and spanned 37 years, Kohn published more than 50 papers in clinical laboratory medicine. He was the first to report the use of CA microbiology filters as solid supports for zone electrophoresis and the separation of hemoglobin phenotypes on CA membranes. Kohn also invented a new electrophoresis chamber and an 8-position stamp applicator especially for use with CA membranes. Beginning in 1957, Kohn pioneered the development of CA techniques for immunoelectrophoresis, counter immunoelectrophoresis, radial immunodiffusion, protein blotting, and immunofixation. He also designed a transport dressing for burn patients and was the first person to describe the use of an enzyme-based dipstick for measuring fingerstick blood glucose concentrations. This short review highlights Kohn’s discovery of CA electrophoresis and his contributions to the development of this procedure. World War II in Europe began toward the end of what W.H. Auden called “a low dishonest decade” (1). The War started on September 1, 1939, when Germany invaded Poland from the west, and 2 weeks later Russia attacked Poland from the east. Faced with 10 000 civilian causalities, the government in Warsaw surrendered on September 27, 1939 (2). More than 200 000 Polish soldiers along with 14 500 officers were taken prisoner by the Russians. The officers were shipped back to prisoner-of-war camps inside Russia. Eight months later, all communication from these prisoners abruptly ended. The fate of most of them is unknown to this day (3). Years later, the bodies of 4500 of these officers were discovered in mass graves near one of the camps in the Katyn Forest outside the Russian city of Smolensk. Many had their hands tied behind their backs; all had a single bullet hole in the back of their head (4). Of the 14 500 Polish officers deported to Russia, fewer than 450 are known to have survived. One of them was a 28-year-old army doctor named Joachim Kohn (5)(6). In 1941, Kohn made his way back to the Allies and joined the British Eighth Army. He served in a field ambulance company until 1947 and received 2 distinguished-service medals (7). In 1950, he took a position in the pathology service at Queen Mary’s Hospital in Roehampton, London. Over the next 37 years until his death in 1987, he published more than 50 papers in clinical laboratory medicine. This short review of his work focuses on his discovery and development of cellulose acetate (CA) 1 electrophoresis. Serum Protein Electrophoresis on CA Membranes In 1950, the year that Kohn entered clinical pathology, E.L. Durrum introduced filter paper as a solid support for the electrophoresis of serum proteins (8)(9). Acceptance of the use of filter paper in routine clinical chemistry was limited, however, because of the 14-h separation times, the tailing of some of the protein bands on the paper, and the inability to make the paper transparent for use with optical densitometers. At a CIBA Foundation Symposium on paper electrophoresis in July 1955, Durrum reviewed the limitations of filter paper and said that “In the future, probably, we will have better supporting media” (10). Fifteen months later, in November 1956, at a Biochemical Society meeting, Kohn presented a new support medium that solved many of the problems of filter paper. He described for the first time the use of a CA microbiology filter as a solid support for zone electrophoresis (11). Unlike filter paper, protein bands on CA membranes were sharply separated, and the membranes could be made transparent with a simple clearing agent. Years later, Kohn wrote that the idea for the use of CA membranes came to him from a remark made by a laboratory salesperson, that standard CA microbiology filters could be made transparent for use with light microscopy (12). In 1954, Richards and Krabeck (13), for example, had described the microscopic counting of bacteria collected on Millipore CA membranes made transparent with immersion oil. Kohn presented his second paper on CA electrophoresis at a protein conference in Bruges, Belgium, in May 1957 (14). The stained and dried CA membranes were made transparent with immersion oil, sandwiched between 2 glass slides, and scanned on a densitometer. Linearity was demonstrated between staining intensity and protein concentration. Kohn ended his talk with the following comments: I shall close this communication by expressing the hope that some of the readers will try this new technique and experiment with it. I have no doubt that the greater experience and better facilities open to them will help in improving both the material and the technique (14) . The keynote speaker at the same Bruges conference was Arne Tiselius, who had won the Nobel Prize in Chemistry in 1948 for his discovery of moving-boundary electrophoresis. In his talk, “Electrophoresis, Past, Present and Future”, the Nobel laureate cited Kohn’s work with CA membranes (15). Later in the conference, at a panel discussion on the use of electrophoresis in the clinical laboratory, Tiselius said: Is it worthwhile to pursue paper electrophoresis to the bitter end? We all realize the danger of electrophoresis in the present form and that you cannot evidently get results of clinical importance. We must keep our eyes open for something very much better. Dr. Kohn has mentioned and described a substrate that seems very promising (16) . After the Bruges conference, Kohn submitted his first full report on CA electrophoresis to the journal Clinica Chimica Acta. This landmark paper was published in the August 1957 issue (17) and described a method in which CA strips 20-cm long by 5-cm wide were run in a standard paper electrophoresis chamber. Five protein fractions plus a prealbumin (transthyretin) band were separated in half the time required for paper media. The strips were stained with nigrosin (Acid Black 2), dried, and made transparent with microscope immersion oil that had a refractive index of 1.474. Protein bands were measured by either elution or optical densitometry of the cleared membrane. Another advantage of CA membranes over paper was that for elution, CA membranes could be completely dissolved in a mixture of ethanol and chloroform. In addition to his work with CA electrophoresis, Kohn in 1957 became the first person to describe the use of a membrane-based dipstick for the measurement of glucose in blood. Fingerstick or earlobe blood was applied to the Ames Clinistix™ glucose oxidase urine dipstick. The results for 545 patient samples were compared with results from 3 alternative quantitative chemical methods. The accuracy of the visual readings on the Clinistix was enhanced by a homemade color chart that Kohn prepared from commercial paints (18). Seven years later, Ames introduced Dextrostix™ specifically for blood sample testing (19)(20). In 1958, Kohn published a series of 3 papers in which he reported redesigning the paper electrophoresis chamber and reducing the size of the CA membranes (21)(22)(23). Conventional horizontal paper electrophoresis chambers contained 2 running buffer tanks separated by an air gap over which the paper strip was mounted. In Kohn’s new design, the 2 buffer chambers were brought together in the middle with no air gap, allowing shorter strips to be used and reducing convection currents by eliminating the air chambers under the mounted solid support media. CA strips 12-cm long and 2.5-cm wide were used with the new chamber. Separation time for serum proteins was reduced from ∼14 h on paper to 2 h with CA membranes in the new chamber. Serum samples of 0.1 μL stained with Ponceau S or nigrosin were adequate for quantitative densitometry or elution. With this new tank and smaller strips, Kohn demonstrated for the first time the separation of hemoglobin phenotypes on CA membranes (24). The Shandon Scientific Company Ltd. later commercialized his new chamber for use with CA membranes (25). Enthusiastic and positive reports on Kohn’s new electrophoresis technique began to appear in the literature in 1959. In July, Smith and Muchison (26) reported their results with CA membranes for the electrophoresis of 400 serum samples performed over an 11-month period. Albert-Recht (27) stained proteins with Lissamine green and made a careful study of quantitative densitometry, and Oriol-Bosch and Voight (28) compared protein recovery between paper and CA membranes. Kohn expanded the capability of CA electrophoresis with the development of a concentration procedure for body fluids that contained low protein concentrations. A dialysis sack was filled with polyethylene glycol (Carbowax™ 20) and then immersed into the sample to be concentrated. Up to 10 mL of urine could be concentrated down to 250 μL in 3–4 h (29). In the 1960 book Chromatographic and Electrophoretic Techniques: Vol. II, Zone Electrophoresis, the editor, Ivor Smith, wrote in the preface that the original plan for the book was to cover only paper electrophoresis, but in “the last year the situation has changed radically. Cellulose acetate methods are in general use” (30). Kohn wrote a 34-page chapter on CA electrophoresis for the book (31). His chapter was the first procedure manual on the technique of CA electrophoresis for serum proteins. Kohn described the low protein-binding nature of CA membranes and their ability to be made transparent with immersion oils with a refractive index of 1.474. Cleared CA membranes were suitable for optical densitometry between 250 and 1000 nm. Typical results were achieved with as little as 0.1 μL of serum with a separation time of 1.5 h. Protein bands were well separated with little to no tailing. The α1γ band was well separated from the much larger albumin band. Ponceau S and nigrosin protein staining techniques were presented. Elution or optical densitometry was used for quantitative analysis. Reference ranges for the 5 fractions were presented along with representative patterns in several disease conditions. Applications for the separation of hemoglobin phenotypes and the separation of radiolabeled proteins were presented. Thyroxine labeled with iodine-131 was shown to migrate with the prealbumin fraction and with a γ fraction between α1 and α2 (31). By the early 1960s, commercial equipment and prepackaged reagents designed specifically for CA membrane electrophoresis became available from Shandon Scientific (25), Beckman(32), Gelman (33), and other companies. Grunbaum et al. (32) described the use of an acetic acid–ethanol mixture as an alternative to immersion oil to make the membranes transparent. Kohn continued to add to the list of applications for CA membranes. He published a method for forminoglutamic acid determination in urine (34), described a periodic acid-Schiff base stain for lipoproteins on CA (35), and reduced the separation time of his original hemoglobin assay from 1 h to 15 min (36) while maintaining good separation of the hemoglobin A2 fraction from hemoglobin C. He also designed a multiposition stamp applicator that dispensed 8 different 1-μL serum samples onto a single CA membrane (37). In 1968, Kohn expanded his chapter on CA electrophoresis for Ivor Smith’s second edition of the zone electrophoresis book (38). Kohn described procedures for the separation of serum and spinal fluid proteins, hemoglobin, and haptoglobin and methods for separation of the isoenzymes of lactic dehydrogenase (EC 1.1.1.27) and leucine aminopeptidase (EC 3.4.11.1). When Davies published a CA electrophoresis procedure for amylase (EC 3.2.1.1) isoenzymes, he acknowledged in his paper the advice received from Kohn (39). Kohn later used this method to demonstrate an increase in the salivary fraction after whole-body irradiation (40). In 1986, 3 months after the Chernobyl nuclear reactor accident in the Ukraine, he proposed that a urine dipstick amylase might be used to screen for radiation exposure (41). Immunoelectrophoresis on CA Membranes Kohn was the first to combine antibodies with CA membranes. In 1957, he adopted the agar gel immunoelectrophoresis (IEP) procedure of Grabar and Williams (42) into a CA-membrane format. Serum proteins were first separated on CA in the usual manner. Before staining, the strip was cut lengthwise through the middle of the protein bands. One half of the strip was stained for protein and the other half placed on a layer of agar gel. A thin strip of filter paper soaked with antibody was placed on the gel ∼0.8 cm below and parallel to the CA strip. Antibody and serum proteins diffused into the gel and formed precipitin arcs between the 2 membranes. The precipitin arcs were stained with Ponceau S and photographed (22)(43). Kohn referred to this technique on CA membranes as a transfer IEP method (31). He later simplified the procedure by eliminating the agar gel. Instead, he placed a thin filter-paper strip soaked in antibody directly on the CA membrane just below the separated bands after protein electrophoresis. Diffusion was allowed to take place directly on the CA membrane (31)(38)(44)(45)(46). The advantages of CA membranes over agar gel for IEP, according to Kohn, were that CA membranes were ready to use and that after staining and drying they became a permanent record of the results. Radial Immunodiffusion and Other Antibody-Based Techniques on CA Membranes Starting in 1959, Kohn developed immunodiffusion techniques for the detection of specific proteins on CA membranes. He essentially adopted Ouchterlony’s (47) double- and single-immunodiffusion methods in agar gel for use with CA membranes. Up to 6 different serum samples or dilutions of a single sample were applied as 1-μL spots in a circle around a single center spot of antibody on the surface of a moistened CA membrane. After incubation, the precipitin arcs were stained in the usual manner. The use of serum dilutions permitted quantitative titers of the target proteins to be estimated (31)(38)(44)(48)(49)(50). With this technique, Kohn measured C-reactive protein concentrations in the sera of burn patients. A correlation was demonstrated between increased C-reactive protein and the severity of the burns (51)(52). In 1963, Kohn developed a nonstick polyurethane foam transport dressing for treating burn patients in the field (53). The Royal Army later adopted this dressing as standard issue (7). Over the years, Kohn continued to publish papers on the immune and nonimmune protein response in burn patients (54)(55)(56). When Mancini et al. (57) demonstrated in 1965 that quantitative immunodiffusion in agar gel was related to the square of the precipitin ring diameter, Kohn adopted their technique to CA membranes. He ran radial immunodiffusion assays with serum spots of 1 μL applied to CA membranes presprayed with antibody. Ring diameters were measured after Ponceau S staining. Results for serum IgA, IgG, and IgM compared favorably (38)(50) with the original agar gel technique reported by Mancini et al. (57). Kohn also developed counterimmunoelectrophoresis (CIE) procedures on CA membranes. In 1968, he described a CIE screening procedure for Hashimoto thyroiditis. Serum was applied at the anode end of a CA membrane and a sample of thyroid extract at the cathode end. If antibody was present in the serum, it formed a precipitin band between the 2 samples during electrophoresis (38). Kohn also described counter-CIE procedures on CA for Australia antigen (58) and α-fetoprotein(58)(59)(60). Agostoni et al. (61) in 1967 were the first to use CA membranes to blot proteins after separation by thin-layer gel filtration. Kohn adopted their procedure and separated serum proteins by thin-layer chromatography on Sephadex™ gel. A moistened piece of CA membrane was placed on the gel, and the proteins were allowed to absorb into the membrane during a 15-min incubation. Protein bands that transferred into the CA membrane were stained for protein or probed with enzyme-labeled antibodies (38)(60)(62). Kohn used enzyme-labeled antibodies in immunofixation techniques to probe for a wide variety of proteins on CA membranes after standard protein electrophoresis, immunodiffusion, and IEP separations (63)(64)(65)(66)(67). Final Publications In 1977 at the age of 65, Kohn retired from Queen Mary’s Hospital. He joined the teaching faculty at the University of Surrey in Guilford and became a consultant in pathology at the Royal Marsden Hospital in Surrey. He soon began to publish papers on the analysis of proteins by nephelometry and became involved in international programs to improve the quality of protein calibrators (68)(69)(70). Despite his involvement in newer techniques of protein measurement, such as laser nephelometry, Kohn never appeared to lose interest in his original CA electrophoresis procedure. Kohn became concerned about the quality of commercial Ponceau S dyes being sold for use with CA electrophoresis and developed a thin-layer chromatography procedure to test various brands of dye for purity (71). In 1986, he joined with 3 other authors in recommending that visual inspection of separated and stained proteins was superior to sole reliance on optical densitometry (72). In January 1987, Kohn and P. Riches reported on a study in which they demonstrated improved resolution of serum proteins after the CA membranes were soaked in a solution containing 0.04 mL/L Tween™ 20 before sample application (73). The resolution of the γ bands increased, and some patient sera showed up to 12 distinct protein bands. Kohn’s last publication was a letter to the editor that appeared in July 1987, 4 months after his death, in Clinica Chimica Acta (74), the same journal that had published his first CA electrophoresis paper almost 30 years before in August 1957 (17). The letter, “Nigrosine the Forgotten Stain”, was written in response to the claims of another author that nigrosin was as sensitive as gold stain for protein detection on CA. Kohn made it clear in the letter that this was not true. Nigrosin is an aniline-based protein dye introduced by Ortega in 1957 for use with paper electrophoresis (75). The dye was water-soluble and produced a blue-black stain with protein. In 1958, Kohn was the first to report on nigrosin as a protein stain with CA membranes (22). Its sensitivity made prealbumin fractions clearly visible even when 0.5 μL of serum was applied. Kohn later reported on the prealbumin concentrations in samples from 4846 patients and did a clinical correlation study on 134 of these patients who had low prealbumin concentrations (76). Kohn continued to use nigrosin for the next 30 years in conventional CA protein separations (31)(60), to stain weak precipitin arcs in immunofixation and IEP procedures (21)(44)(48)(52)(63)(77)(78), and in a CIE procedure for α-fetoprotein (58). In the letter, Kohn provided the reagent formulation for the working dye and details on the best staining conditions, and warned about the importance of shaking the membrane during staining. He ended with a reference to an unpublished study in which he along with coworkers found that metallic gold stain for protein was at least 20 times more sensitive than nigrosin. Kohn’s final letter demonstrated the lack of self-interest found in many of his publications. For 30 years, Kohn advocated the use of nigrosin as a sensitive stain for proteins, and yet he made the effort to deny inflated claims by others about its performance. In addition, there is no evidence in any of his publications that he had any stake in the commercial side of his inventions and discoveries. When he mentioned, for example, a particular brand name of an electrophoresis chamber, he would add that other brands would work as well (79), despite the fact that the electrophoresis chamber he designed was being sold by one manufacturer as the Kohn chamber (25). He would often list in his publications the names of up to 5 companies from which CA membranes could be purchased (38). Kohn discovered CA electrophoresis, invented a new buffer chamber, and developed an 8-position stamp applicator. He was the first to develop and publish on the use of antibodies with CA membranes, but he appears never to have patented any of these devices or applications. One of his inventions was a waste-trap in-place sterilizing unit designed for sinks. Kohn built this unit in response to the high rate of bacterial contamination found in hospital sink waste traps. At the end of the paper that described this device he indicated that the design had been submitted to the National Research and Development Council, a government research funding organization, for them to patent (80). In 1985, Kohn was made an Honorary Member of the Association of Clinical Biochemists (81). He joined a list that at the time included D.D. Van Slyke, P. Astrup, S.A. Berson, F.W. Sunderman, and P. Trinder. Joachim Kohn died on March 31, 1987, and was survived by his wife, daughter, and brother (82). 1 Nonstandard abbreviations: CA, cellulose acetate; IEP, immunoelectrophoresis; and CIE, counterimmunoelectrophoresis. 1 Auden WH. September 1, 1939. Mendelson E eds. Selected poems new edition 1989 : 86 -89 Vintage International New York. . 2 Goralski R. World War II almanac: 1931–1945. A political and military record 1984 : 90 -96 Bonanza Books New York. . 3 Zawodny JK. Death in the forest: the story of the Katyn Forest massacre 1962 : 235pp University of Notre Dame Press Notre Dame, IN. . 4 Raszeja S, Chroscielewski E. Medicolegal reconstruction of the Katyn forest massacre. Forensic Sci Int 1994 ; 68 : 1 -6. 5 Investigation of the murder of thousands of Polish officers in the Katyn Forest near Smolensk, Russia. Select Committee to Conduct an Investigation of the Facts, Evidence, and Circumstances of the Katyn Forest Massacre. Part 4. 82nd Congress, 2nd Session. Washington, DC: US Government Printing Office, April 16–19, 1952:538 [The publication of the hearings before Congress contains a reproduction of a list of the names of the survivors prepared in January 1946. Joachim Kohn’s name is No. 26 on page 538 in part 4 of the document.]. 6 Indeks Represjonowanych.www.indeks.karta.org.pl/szczegoly.asp?id=21174 (accessed June 3, 2005). [The Karta Foundation lists on their web site the names along with additional information on each of the survivors. This URL is for Joachim Kohn’s page.]. 7 Obituary. J Kohn. BMJ 1987;294:1105.. 8 Durrum EL. A microelectrophoretic and microionophoretic technique. J Am Chem Soc 1950 ; 72 : 2943 -2948. 9 Rosenfeld L. Origins of protein electrophoresis in paper. [Letter] Clin Chem 1981 ; 27 : 1948 -1949. 10 Durrum EL. The future of the technique in its application to clinical research and routine analysis. Wolstenholme GEW Millar ECP eds. CIBA Foundation symposium on paper electrophoresis 1956 : 197 -204 Little, Brown and Company Boston. . 11 Kohn J. A new supporting medium for zone electrophoresis. [Abstract] Biochem J 1957 ; 65 : 9P . 12 Kohn J, Riches PG. A review of the development and application of cellulose acetate membrane electrophoresis. Ritzman S eds. Physiology of immunoglobulins: diagnostic and clinical aspects, Vol. 1. Protein abnormalities 1982 : 15 -27 Alan R. Liss New York. . 13 Richards OW, Krabek WB. Visibilizing microorganisms on membrane filter surface. J Bacteriol 1954 ; 67 : 613 . 14 Kohn J. Membrane filter electrophoresis. Peeters H eds. Protides of the biological fluids, proceedings of the Fifth Colloquium, Bruges, 1957 1958 : 120 -125 Elsevier Amsterdam. . 15 Tiselius A. Electrophoresis, past, present and future. Peeters H eds. Protides of the biological fluids, proceedings of the Fifth Colloquium, Bruges, 1957 1958 : 8 -9 Elsevier Amsterdam. . 16 Peeters H. Standardization of electrophoresis in view of its clinical use. Peeters H eds. Protides of the biological fluids, proceedings of the Fifth Colloquium, Bruges, 1957 1958 : 245 -254 Elsevier Amsterdam. . 17 Kohn J. A cellulose acetate supporting medium for zone electrophoresis. Clin Chim Acta 1957 ; 2 : 297 -303. 18 Kohn J. A rapid method of estimating blood-glucose ranges. Lancet 1957 ; 270 : 119 -121. 19 Cohen SL, Legg S, Bird R. A bedside method of blood-glucose estimation. Lancet 1964 ; 284 : 883 -884. 20 Kohn J. Dextrostix estimations of blood-sugar. [Letter] Lancet 1965 ; 286 : 438 . 21 Kohn J. A micro-electrophoretic method. [Letter] Nature 1958 ; 181 : 839 -840. 22 Kohn J. Small-scale membrane filter electrophoresis and immuno-electrophoresis. Clin Chim Acta 1958 ; 3 : 450 -454. 23 Kohn J. Small-scale and micro-membrane filter-electrophoresis and immuno-electrophoresis. Peeters H eds. Protides of the biological fluids, proceedings of the Sixth Colloquium, Bruges, 1958 1959 : 74 -78 Elsevier Amsterdam. . 24 Kohn J. Rapid small-scale electrophoresis of abnormal haemoglobins. [Abstract] Trans R Soc Trop Med Hyg 1958 ; 52 : 304 . 25 New instruments, materials and tools. [Editorial] J Sci Instruments 1961 ; 38 : 309 -310. 26 Smith DC, Murchison W. The routine use of cellulose acetate strips in serum protein zone electrophoresis. J Med Lab Technol 1959 ; 16 : 197 -200. 27 Albert-Recht F. Quantitation of plasma proteins on cellulose acetate strips. Clin Chim Acta 1959 ; 4 : 627 -638. 28 Oriol-Bosch A, Voigt KD. Untersuchungen zur elektrophoretischen trennung von serumeiweisskorpern an einer cellulose-acetat-folie. Peeters H eds. Protides of the biological fluids, proceedings of the Seventh Colloquium, Bruges, 1959 1960 : 332 -338 Elsevier Amsterdam. . 29 Kohn J. A simple method for the concentration of fluids containing protein. [Letter] Nature 1959 ; 183 : 1055 . 30 Smith I. Preface. Smith I eds. Chromatographic and electrophoretic techniques, Vol. II. Zone electrophoresis 1960 : vii -viii Interscience New York. . 31 Kohn J. Cellulose-acetate electrophoresis and immuno-diffusion techniques. Smith I eds. Chromatographic and electrophoretic techniques, Vol. II. Zone electrophoresis 1960 : 56 -90 Interscience New York. . 32 Grunbaum BW, Zec J, Durrum EL. Application of an improved microelectrophoresis technique and immunoelectrophoresis of the serum proteins on cellulose acetate. Microchem J 1963 ; 7 : 41 -53. 33 Bartlett RC. Rapid cellulose acetate electrophoresis. Clin Chem 1963 ; 9 : 317 -324. 34 Kohn J, Mollin DL, Rosenbach LM. Conventional voltage electrophoresis for forminoglutamic-acid determination in folic acid deficiency. J Clin Pathal 1961 ; 14 : 345 -350. 35 Kohn J. A lipoprotein staining method for zone electrophoresis. [Letter] Nature 1961 ; 189 : 312 -313. 36 Kohn J. Separation of haemoglobins on cellulose acetate. J Clin Pathol 1969 ; 22 : 109 -111. 37 Kohn J. A multi-sample applicator for zone electrophoresis. Clin Chim Acta 1967 ; 18 : 65 -68. 38 Kohn J. Cellulose acetate electrophoresis and immuno-diffusion techniques. Smith I eds. Chromatographic and electrophoretic techniques, Vol. II. Zone electrophoresis 1968 : 84 -146 Interscience New York. . 39 Davies TJ. A fast technique for the separation and detection of amylase isoenzymes using a chromogenic substrate. J Clin Pathol 1972 ; 25 : 266 -267. 40 Barrett A, Jacobs A, Kohn J, Raymond J, Powles RL. Changes in serum amylase and its iosenzymes after whole body irradiation. BMJ 1982 ; 285 : 170 -171. 41 Kohn J. Measurement of amylase activity-a useful indication of tissue damage after major radiation accidents?. [Letter] BMJ 1986 ; 292 : 1523 -1524. 42 Grabar P, Williams CA. Methode immuno-electrophoretique d’analyse de melanges de substances antigeniques. Biochim Biophys Acta 1955 ; 17 : 67 -74. 43 Kohn J. An immuno-electrophoretic technique. [Letter] Nature 1957 ; 180 : 986 -987. 44 Consden R, Kohn J. Cellulose acetate as a medium for immuno-diffusion. Nature 1959 ; 183 : 1512 -1513. 45 Kohn J. Electrophoresis and immunodiffusion techniques on cellulose acetate membranes. Olson RE eds. Methods in medical research 1970 ; Vol, 12 : 243 -260 Year Book Medical Publishers Chicago. . 46 Kohn J. Gel immunoelectrophoresis. Simpson CF Whittaker M eds. Electrophoretic techniques 1983 : 119 -148 Academic Press London. . 47 Ouchterlony O. Handbook of immunodiffusion and immunoelectrophoresis 1968 : 215pp Ann Arbor Science Publishers Ann Arbor, MI. . 48 Kohn J. Electrophoretic and immunological studies on some body fluids in normal and pathological conditions and a preliminary communication on the separation of proteins of the labyrinthine fluids. Peeters H eds. Protides of the biological fluids, proceedings of the Seventh Colloquium, Bruges, 1959 1960 : 67 -70 Elsevier Amsterdam. . 49 Kohn J. Simplified procedure for immunodiffusion technique on cellulose acetate. [Letter] Nature 1968 ; 217 : 1261 -1262. 50 Kohn J. Double diffusion in cellulose acetate membrane (CAM). Williams CA Chase MW eds. Methods in immunology and immunochemistry, Vol. III. Reactions of antibodies with soluble antigens 1971 : 168 -174 Academic Press New York. . 51 Kohn J. C-Reactive protein in burns. [Letter] Lancet 1960 ; 1 : 334 . 52 Kohn J. Occurance and behaviour of C-reactive protein in burns. Peeters H eds. Protides of the biological fluids, proceedings of the Eighth Colloquium, Bruges, 1960 1961 : 315 -318 Elsevier Amsterdam. . 53 Kohn J. A transport dressing for extensive burns. J R Army Med Corps 1963 ; 109 : 199 -202. 54 Kohn J, Cort DF. Immunoglobulins in burned patients. [Letter] Lancet 1969 ; 293 : 836 -837. 55 Gerrard J, Kohn J, Turner MW. A non-immunoglobulin γ-protein of human serum present in increased amounts in patients with severe burns. Clin Chim Acta 1972 ; 40 : 243 -248. 56 Kohn J. Abnormal immune response in burns. Postgrad Med J 1972 ; 48 : 335 -337. 57 Mancini G, Carbonara AO, Heremans JF. Immunochemical quantitation of antigens by single radial immunodiffusion. Immunochemistry 1965 ; 2 : 235 -254. 58 Kohn J, Kahan M. Countercurrent immunoelectrophoresis on cellulose acetate. J Immunol Methods 1976 ; 11 : 303 -309. 59 Kohn J, Weaver PC. Serum-α1-fetoprotein in hepatocellular carcinoma. Lancet 1974 ; 304 : 334 -336. 60 Kohn J. Cellulose acetate electrophoresis and immuno-diffusion techniques. Smith I eds. Chromatographic and electrophoretic techniques, Vol. II. Zone electrophoresis 1976 : 90 -137 Year Book Medical Publishers Chicago. . 61 Agostoni A, Vergani C, Lomanto B. Characterization of serum proteins by thin-layer gel filtration combined with immunodiffusion. J Lab Clin Med 1967 ; 69 : 522 -529. 62 Kohn J. An immunochromatographic technique. Immunology 1968 ; 15 : 863 -865. 63 Kohn J, Riches PG. A cellulose acetate immunofixation technique. J Immunol Methods 1978 ; 20 : 825 -831. 64 Kahan M, Riches PG, Kohn J. Paraproteinaemia in neurological disease: incidence, associations, and classification of monoclonal immunoglobulins. J Clin Pathol 1980 ; 33 : 617 -621. 65 Kohn J. The use of enzyme-linked second antibodies in immunodiffusion techniques on cellulose acetate membranes. Peeters H eds. Protides of the biological fluids, proceedings of the Thirty-First Colloquium, 1983 1984 : 1083 -1086 Pergamon Press Oxford. . 66 Aguzzi F, Kohn J, Merlini G, Riches PG. More on immunofixation vs immunoelectrophoresis. [Letter] Clin Chem 1984 ; 30 : 1113 . 67 Kohn J, Riches PG, Raymond JC. The use of alkaline-phosphatase conjugated second antibody for the enhancement of immunoprecipitation techniques on cellulose acetate membranes. J Immunol Methods 1985 ; 76 : 11 -16. 68 Whicher JT, Hunt J, Perry DE, Hobbs JR, Fifield R, Keyser J, et al. Method-specific variations in the calibration of a new immunoglobulin standard suitable for use in nephelometric techniques. Clin Chem 1978 ; 24 : 531 -535. 69 Warren C, Whicher J, Kohn J. The use of concanavalin A to measure acute phase proteins by laser nephelometry. J Immunol Methods 1980 ; 32 : 141 -150. 70 Kohn J, Whicher J, Warren C, O’Kelly T. The use of lectins to measure acute phase proteins in the serum or plasma of man and animals during inflammation and tissue breakdown. FEBS Lett 1980 ; 109 : 257 -260. 71 Kohn J, Mepham BL. Problems of Ponceau S quality and nomenclature. Clin Chim Acta 1973 ; 44 : 151 -152. 72 Aguzzi F, Kohn J, Petrini C, Whicher JT. Densitometry of serum protein electrophoretograms. [Letter] Clin Chem 1986 ; 32 : 2004 -2005. 73 Riches PG, Kohn J. Improved resolution of cellulose acetate membrane electrophoresis. Ann Clin Biochem 1987 ; 24 : 77 -79. 74 Kohn J. Nigrosine the forgotten protein stain. [Letter] Clin Chim Acta 1987 ; 166 : 335 -336. 75 Ortega M. Use of ‘Nigrosine’ for staining proteins after electrophoresis on filter paper. [Letter] Nature 1957 ; 179 : 1086 -1087. 76 Harris RI, Kohn J. The pre-albumin fraction: a useful parameter in the interpretation of routine protein electrophoresis. J Clin Pathol 1974 ; 27 : 986 -989. 77 Kohn J. Immuno-diffusion technique on cellulose acetate. Peeters H eds. Protides of the biological fluids, proceedings of the Ninth Colloquium, Bruges, 1961 1962 : 120 -122 Elsevier Amsterdam. . 78 Kohn J. Cellulose acetate membrane (CAM) electrophoresis. Williams CA Chase MW eds. Methods in immunology and immunochemistry, Vol. II. Physical and chemical methods 1968 : 22 -25 Academic Press New York. . 79 Kohn J. Cellulose acetate electrophoresis. Race GJ eds. Laboratory medicine 1976 ; Vol. 1 : 1 -15 Harper & Row Philadelphia. . 80 Kohn J. A waste-trap-sterilising method. Lancet 1970 ; 296 : 550 -551. 81 ACB. Honorary members of the Association of Clinical Biochemists. www.acb.org.uk/History/Officers/HonMem.htm (accessed June 5, 2005).. 82 Obituary. Kohn, Jaochim [sic]. London Times 1987;April 3:17.. © 2005 The American Association for Clinical Chemistry This article is published and distributed under the terms of the Oxford University Press, Standard Journals Publication Model (https://academic.oup.com/journals/pages/open_access/funder_policies/chorus/standard_publication_model)
TI - Joachim Kohn (1912–1987) and the Origin of Cellulose Acetate Electrophoresis
JO - Clinical Chemistry
DO - 10.1373/clinchem.2005.056572
DA - 2005-10-01
UR - https://www.deepdyve.com/lp/oxford-university-press/joachim-kohn-1912-1987-and-the-origin-of-cellulose-acetate-RI4M6FvDFk
SP - 1896
VL - 51
IS - 10
DP - DeepDyve
ER -