Levels of HIV-1 in bottom compartment of Transwell for two semi-solid gels, HEC and MC (n ≥ 4 independent experiments). Experimental results are normalized to controls where no gel was applied to the membrane, such that % control = RLUbottom,experiment/RLUbottom,control. Additional control experiments were performed in which an equivalent amount of gel was mixed in to solutions. For 0-, 4-, and 8- hour incubations, there was a log reduction in levels of HIV-1 in the bottom compartment.