Methodological aspects affecting the infectivity of Chlamydia pneumoniae in cell cultures in vitro

The effect of culture medium, washing, temperature, and sonication on the infectivity of Chlamydia pneumoniae for HL cells in experiments with heparin or heparinase treatment was studied. The presence of fetal calf serum (FCS) was necessary, and simple washing of elementary bodies increased their infectivity titer. Prolonged sonication was detrimental. Detailed description of the experimental conditions is necessary in studies of chlamydial attachment and infectivity.