(A) [3H] thymidine-labeled TF were added to IPEC-J2 monolayers at infection doses of 10, 15, and 20 × 106 trichomonads and co-cultured for 1, 6, 11, and 24 hours. Each data point represents 3–4 replicates. (B) The adherence of [3H] thymidine labeled-TF to IPEC-J2 cell monolayers (24 mm2 polycarbonate inserts) was saturable at infecting doses ≥ 40 × 106 TF per ml (highest dose of TF tested was 160 × 106 TF per ml). Each data point represents 3–4 replicates.