A simple and rapid method is described for the large-scale isolation o
f cumulus cell-free, zona pellucida-intact equine oocytes. Aspiration
of palpable antral follicles present on frozen-thawed equine ovaries w
as accomplished using a constant vacuum source. The resultant follicul
ar fluid, oocytes, and particulate matter were then filtered through a
series of nylon screens of alternating mesh openings in combination w
ith sodium citrate-containing buffer to a final volume of approximatel
y 20 ml. This fluid was transferred to scored Petri dishes and a stere
omicroscope was used to locate the oocytes for further processing or s
torage. The methodology described is inexpensive, time-efficient, and
the recovery rate is similar to or better than other methods previousl
y described for equine oocyte recovery. Collected oocytes are adequate
for biochemical evaluation of the equine zona pellucida (EZP) as well
as sperm-egg binding assays.