A reproducible modified method for direct preparation of chorionic villi cytogenetic analysis.

Chorionic villi are finger like projections, which surrounds the embryonic sac in early pregnancy and will later form the placenta. The outer layer of the chorionic villi consists of trophoblast cells. These cells are actively dividing and can be used for direct preparation or short-term culture for prenatal diagnosis of chromosomal abnormalities. We herein describe a 100% reproducible modified technique for one day direct culturing (direct prepara-tion) of trophoblast cells. Direct preparation of chorionic villi provides the physician with additional diagnostic information during prenatal diagnosis and genetic counseling. Direct preparation also eliminates the risk of maternal cell contamination. This method was 100% reproducible provided all the precautions mentioned herewith were taken into consideration and can be completed in 45 minutes upon arrival of the samples in the laboratories.