p24 antigen production after 
STERILE
Two ectocervical tissue biopsies were collected at baseline and placed immediately in two separate sterile cryovials filled with chilled RPMI 1640 media (Life Technologies, Carlsbad, CA) containing 10% fetal bovine serum (ATCC, Manassas, VA) and 100 U/ml penicillin and 100 µg/ml streptomycin (Thermo Fisher Scientific, Waltham, MA) (cRPMI) (