Twenty-four-hour kill curves for amphotericin B at a concentration equivalent to its MIC against C. albicans TO3 in various media. Symbols for amphotericin B: ■, in RPMI; ▴, in serum; ●, in heat-inactivated serum; ⧫, in proteinase K-treated serum. Symbols for growth control: □, in RPMI; ×, in serum; ○, in heat-inactivated serum; ✕⃒, in proteinase K-treated serum.