http://www.actazool.org/paperdetail.asp?id=10965

The study examined an improved immunofluorescence double-staining assay for identifying the quality of mouse blastocysts. Our methodology included the following improvements: the blastocysts were treated with Anti-sheep Whole Serum with 1/5 dilution for 30 min, and then treated with Guinea Pig Complementary Serum containing with 5.3 μg/ml Propidium Iodide and Bisbenzimide, with 1/5 dilution for 90 min. Concentrations of sodium citrate were also increased. Squashing must be initiated before counting embryonic cell numbers .The potentially negative effect of serum on antibody and complement, light-tight status and rapid operation must be taken into account. Following double-staining, the inner cell mass ( ICM ) cells were colored blue, but the trophectoderm ( TE ) ones were pink, and these two cell types could be clearly distinguished. We conclude that this improved double-staining assay can be used to assess the quality of mouse blastocysts more concisely and efficiently [Acta Zoologica Sinica 54(5): 928–932, 2008].