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 DNA synthesis by [14C]-thymidine incorporation using 96-well Cytostar-T scintillating microplates without the need to separate labeled DNA onto filters. The system is designed for high-throughput (HT) screening and provides real-time measurement of DNA synthesis. The company's [3H]- Thymidine Uptake Assay Kit incorporates the scintillation proximity assay (SPA). Considered the gold standard ...