Figure 6

FITC-PIF is selectively taken up by bovine blastocysts. Blastocysts were exposed to either 5 μg/ml FITC-PIF or scrambled FITC-PIF for 30 minutes in culture and specific binding was evaluated by washing off unattached fluorescent peptide. Blastocysts nuclei were also counterstained using DAPI, vital stain. Embryos were fixed, stained and evaluated by using a fluorescent microscope using two different wave lengths. b+c (FITC-PIF or scrambled FITC-PIF and DAPI stain), b, (FITC-PIF or scrambled FITC-PIF alone), c (DAPI stain alone). Part A: FITC-PIF binds to cultured blastocysts. Part B: FITC-PIF binds to expanded blastocysts. Part C: FITC-PIF binds to hatched blastocysts Part D. In contrast, 5 μg/ml FITC-scrambled PIF, used as control did not bind. (magnification × 40).