The
relatively new technique ei called PCR. This technique
allows us to generate thousands to millions of copies of a
particular DNA sequence from chromosomes X et Y.
The second
operation, which is electrophoresis, is able to separate
the fragments of X and Y. They form two distinct and
individualised strips, visible under UV lightings.
A biopsy
that shows a single strip X identifies then a female
embryo while the presence of two strips (both X and Y)
identifies a male embryon.
The majority
of females are transferred on the same day to heifer
recipients.
