An [¹²⁵I]iododesoxyuridine utilization assay to measure the survival of human cells after various freezing programs

Abstract

An ¹²⁵IUDR incorporation assay is described which has been used to assess cell viability after freeze-thawing. A −10 °C/ min program and a −1 °C/min program, to be used on a Cryoson BV4 biological freezer, were designed to minimize the latent heat plateaus. These programs and a Knight and Farrant two-step program were compared with respect to survival of cells obtained from patients with malignant ascites and the established Chang cell line, originally from normal human liver. All the programs tested gave survival rates above 44% and the −5 °C/min program gave the best overall rates.