Cephradine (Anspor) is a beta-lactam, first-generation cephalosporin antibiotic with bactericidal activity.

Cells Are seeded in six-well culture plates (9.6 cm2, growth area) at a density of 105 cells/cm2. At 2 days postseeding, the medium is removed and cells are washed twice with pH 6.0 uptake buffer. Independent studies are performed for each drug solution at 1 mg/mL made in pH 6.0 uptake buffer. At each time point (10, 20, 30, 45, 60, 90 min), drug solution is removed and cells are washed three times with ice-cold pH 6.0 uptake buffer. One milliliter of Milli-Q water is added to each well and incubated for 30 min at 25 °C. Cells are harvested and sonicated for 1-2 min. ZnSO4 solution (8%, 200 mL) is added to the cell lysate, vortexed rigorously, and centrifuged for 5 min at 3000 rpm. After filtration of the supernatant through a membrane filter (0.45 mm), samples are analyzed by HPLC. (Only for Reference)