Figure 7. MTT assay of porcine tissue specimens fully submerged in 1% Tenofovir clinical gel at 37 °C.

Freshly excised tissue specimens were incubated while fully submerged in 1% Tenofovir gel and maintained at 5% CO₂ and 37 °C for different amounts of time. After incubation, the tissue specimens were removed from the gel, washed five times, and subjected to the MTT assay. Results were computed as a tetrazolium reductase index (TR index; absorbance per mg tissue) by dividing the absorbance the formazan product at 570 nm by the dry weight of the tissue specimen. Control samples were fresh untreated tissue specimens (1.6 h post mortem). To obtain deactivated (dead) samples, tissue specimens were boiled in water for 2h to inactivate enzyme activity. Data shown represent mean ±SE of 3-4 replicates.