culture medium
based on Dulbecco’s modified Eagle’s medium and Ham’s
F-12 nutrient mixture (1:1) and containing 0.75% BSA
(essentially fatty acid free; Sigma–Aldrich, St. Louis, MO,
USA), 5% serum (2.5% Fetal Bovine Serum; Greiner Bio-One,
Frickenhausen, Germany; and 2.5% Newborn Calf Serum;
Sigma–Aldrich), 2.5% penicillin–streptomycin, and 2%
amphotericin B. Cell count and cell viability testing were
performed with a Bürker Counting Chamber (W. Schreck,
Hofheim, Germany) and trypan blue. Bovine oviductal
epithelial cells were diluted to a density of 1 106 cells/mL
and seeded in three different culture systems as described
in the following. The culture mediumwas renewed after 24
hours and subsequently every 48 hours.