Abstract

Cell Proliferation Assays Suppliers of Cell Proliferation Assays Courtesy of Zymed LaboratoriesMouse anti-PCNA (PC10)-stained colonic mucosa. Scientists often require rapid and accurate measurement of viable cell number and cell growth. These researchers traditionally assess cell viability via membrane integrity (e.g., trypan blue exclusion), and cell proliferation via the incorporation of labeled nucleotides (e.g., [3H]-thymidine) into newly synthesized DNA during cell division. Work to improve viability detection methods is yielding assays that enumerate cells more rapidly, precisely, and safely. Likewise, new technology to detect proliferating cells based on metabolic activity is producing rapid, safe, and reliable alternatives to DNA-related methodologies. One of the most familiar and widely used methods for quantifying cell proliferation is the measurement of tritiated thymidine ([3H]-thymidine) incorporation. Cells incorporate the labeled DNA precursors into newly synthesized DNA, such that the amount of incorporation, measured by liquid scintillation counting, is a relative measure of cellular proliferation. Unfortunately, this technique is time-consuming and labor-intensive, and exposes the researcher to scintillation fluid and tritium, both of which are toxic. Amersham Pharmacia Biotech of Piscataway, N.J., offers both a [14C]-thymidine and a [3H]-thymidine uptake assay system, each designed to decrease radioisotope handling. The Thymidine Uptake [14C] Cytostar-T™ Assay measures