1 Departments of Biophysics and Genetics, and Pediatrics, University of Colorado Medical Center, Denver, Colorado 80220
The ability to examine amniotic fluid obtained by amniocentesis during the second trimester of pregnancy is a significant new advance in the practice of clinical genetics.1 We here report a rapid and accurate method for determining fetal sex, which should be useful when the pregnant woman is a carrier of a serious sex-linked disease such as muscular dystrophy or hemophilia. The method makes use of the selective concentration of fluorescent stains by the Y chromosome in interphase cells.2,3 Recently two observers have reported their preliminary observations on amniotic fluid cells using fluorescent techniques.4,5