Adaptation of the primer extension preamplification (PEP) reaction for preimplantation diagnosis: single blastomere analysis using short PEP protocols.

Primer extension preamplification (PEP) was first described as a method for whole genome amplification, starting from a single cell, originally a spermatozoon, in order to perform genetic recombination studies. Its usefulness for preimplantation diagnosis was shown soon after; the only drawback was the length of the procedure (> 14 h). We have developed a shorter PEP protocol for single human blastomeres, enabling us to examine several genetic loci of interest in human genetic diseases with a good amplification efficiency.