Viability of inner cell mass versus trophectodermal cells of frozen‐thawed horse embryos

Abstract

Summary Fluorescein diacetate (FDA), a fluorogenic vital stain, was used in conjunction with a silicon‐intensified target (SIT) camera and computer‐based image analysis to estimate the viability of cells of the inner cell mass (ICM) and trophectoderm (TE) of freshly collected and frozen‐thawed horse embryos. Fluorescence intensities were greater (p<0.02) for fresh ICM (0.1500) and TE (0.1686) than for frozen‐thawed ICM (0.0323) and TE (0.0694). Fluorescence intensity ratios (ICM:TE) also differed (p<0.004) between fresh (0.966) and frozen‐thawed (0.482) embryos. These results indicate that 1) the use of FDA coupled with SIT camera image analysis is a repeatable, objective method for assessing embryo viability and 2) the freeze‐thaw process is more detrimental to ICM cells than to TE cells of horse embryos.