Figure 4: Progressive motility in uncentrifuged, SLC-4.5, and SLC-25 sperm samples ( 𝑛 = 4 ) during cold storage at 6°C for up to 72 h. Note: stallion spermatozoa were prepared by SLC-4.5 and SLC-25 (4.5 mL extended semen on top of 4 mL Androcoll-E in a 12-mL centrifuge tube, and 25 mL extended semen on top of 20 mL Androcoll-E in a 100 mL conical glass centrifuge tube, resp.); uncent = uncentrifuged control.