D. Hlinka et al., Experimental attempts to extend the current preimplantation genetic diagnosis with individual karyotypization of human blastomeres, REPROD NUTR, 41(1), 2001, pp. 91-106
The drug-induced chromosome condensation using okadaic acid, a potent prote
in phosphatase inhibitor, was studied in day 1 to day 4 (D1-D4) spare human
preimplantation embryos. In order to obtain cells for genetic tests, we de
veloped a modified displacement blastomere biopsy method. During the okadai
c acid treatment, approximately 40% of biopsied cells were lost due to heav
y changes of the plasma membrane; this detrimental effect of okadaic acid d
iffered markedly with the respect to the age of embryos. In comparison with
the natural embryonic mitotic index, day 1 and day 2 embryonic cells gave
increased yields of chromosome spreads (up to 51% of the initial D1-D2 cell
number); on days 3 and 4 we were not able to obtain from surviving cells m
ore than 31% blastomeres with condensed chromosomes (9% of total D3-D4 cell
number). All chromosome spreads were successfully used for recycling in G-
banding and subsequent FISH analysis.