Fig. 4. Infection of cultured cells with A. fumigatus conidia does not induce cellular cytotoxicity. A549 (A) or J774 (B) cells were incubated with A. fumigatus conidia for 6, 12 or 24 hours and then the supernatant was assayed for LDH activity. Infected samples contained cells plus conidia and uninfected samples contained cells only. Lysed represents uninfected cells that were treated with 1% Triton X-100 prior to sampling. Samples were incubated with LDH substrate for 5 minutes and then the absorbance was read on a microplate reader at 490 nm. *P<0.05.