New staining methods and automated instruments are now available to ev
aluate the sperm cell in vitro. Individual compartments of the sperm c
ell, such as the nucleus and the plasma and acrosomal membranes, may b
e investigated, as well as the cell, function as shown by mitochondria
activity and capacitation. Various probes are used and they can be an
alyzed by direct light or fluorescent microscopy or by flow cytometry.
The automated instruments allow objective and accurate analysis and q
uantification as well as the ability to evaluate large population of c
ells in a shorter time, thus providing accurate evaluation of sperm qu
ality. However, before these test can be recommended for routine clini
cal and investigational use, in the stallion, they need to be confirme
d on a larger number of stallions and their correlation with tradition
al semen parameters and with stallion fertility has to be demonstrated
. (C) 1997 by Elsevier Science Inc.