A method for establishing the sex of chick embryos before the appearan
ce or morphological differences between males and females has been dev
eloped. DNA was isolated from 5-7-day-old embryos by proteinase K dige
stion and subjected to polymerase chain reaction (PCR) amplification w
ith W-chromosome specific primers. Sexing can be achieved within 1 day
using as little as 1 ng template DNA.