Hi,

In this paragraph:

Researchers inoculated cell media with each of three virulent S. pneumoniae strains (strains I, II, and III) to a final concentration of 1.25 × 109 CFU/ml, where CFU is colony-forming-units. After 7 h (during log-phase growth), the media was filtered to remove the bacterial cells. Then alveolar epithelial cells (AECs) were incubated in this “conditioned” media for 7 h. An assay was used to show localized expression of 53BP1 and/or γH2AX in the AECs using fluorescently tagged antibodies (Figure 1).

What does the conditioned media refer to? Does conditioned media mean with bacteria?

Thank you