Quality Assurance Considerations in Cryptosporidium Antibody Tests
Abstract
Quality Assurance Considerations in Cryptosporidium Antibody Tests Floyd Frost * , Tim Muller , and Twila Kunde Lovelace Clinic Foundation 2425 Ridgecrest Drive S.E. Albuquerque, NM 87108 Gunther Craun Gunther F. Craun and Associates 101 West Frederick St., Suite 205 Staunton, VA 24401 Priest et al. ( 12 ) reported a comparison of serological techniques to detect responses to two Cryptosporidium antigens. They compared a low-cost minigel format blot assay that we developed with a Centers for Disease Control and Prevention (CDC)-developed enzyme-linked immunosorbent assay (ELISA) and a large-format gel. The minigel analysis was performed in a British Columbia laboratory. The minigel and large-format gel detected similar positive and negative responses to the 15- and 17-kDa antigens; however, the CDC ELISA had 23% false-positive responses and 12% false-negative responses to the 15- to 17-kDa antigen. For the 27-kDa antigen, the large-format gel detected more positive responses than did either the minigel or ELISA. In 1996, we trained the British Columbia staff in Albuquerque to conduct our minigel assay and provided copies of our quality assurance (QA) procedures. These procedures require computer imaging of the blots and rejecting blots with a weak positive control (PC) or when the coefficient