Cell free HIV-1 virus can infect inner and outer foreskin polarized explants.

Methods First, we have developed cryopreservation methods that allow infection of foreskin tissue explants after thawing (654 +/178.3 pg of p24/gr of tissue) and provide comparable infection rates to fresh samples( 716.5 +/446pg of p24/gr of tissue). Second, we have developed an ex vivo assay that uses human foreskin explants to replicate the polarized viral entry. After 12h of polarized exposure, HIV entering the explant is amplified for 6 days of culture with activated PBMCs and measured using p24 ELISA.