Amniocyte clones for prenatal cytogenetics

Amniotic fluid cells were processed in situ on coverslips in 1,429 consecutive cases from Colorado and Arizona. Two true chromosome mosaics were differentiated from 39 pseudomosaics with clarity by the method described here in detail. The culture failure rate was 1--2% and the error rate was 0% in both laboratories. The time in culture prior to the initial harvest for the last 329 cases was 8.7 days.