Résumé : Objective: To evaluate the possibility of using polymerase chain reaction (PCR) technology for preimplantation diagnosis for Tay-Sachs disease. Design: Polymerase chain reaction on single human blastomeres. Setting: Bad quality embryos from IVF analyzed in an academic research genetics lab. Interventions: Patients underwent standard IVF procedures as infertility treatment. Results: Amplification was seen in 89.5% of the blastomeres; only one blank was contaminated. Conclusion: The technique of PCR on single blastomeres is ready to be used in clinical preimplantation diagnosis for Tay-Sachs disease.