Inactivation by autoclaving

An autoclave inactivates cells by heat and pressure. It is a much more aggressive treatment than heat alone. A cell will completely disintegrate into tiny pieces after autoclave treatment. As discussed in Cell size range BactoBox® detects objects with a sphere-equivalent diameter of 0.5–5.0 µm and therefore the debris is most likely not detectable by BactoBox® measurements.

When a culture is autoclaved, there may still be a few cell-like objects left, but the concentration will be reduced by more than three orders of magnitude. Whatever objects may remain constitute a negligible fraction of the initial cell population.

Custom gating is not meaningful for autoclaved bacteria. Gating cannot recover what is not detected.

Autoclaving disintegrates cells. The dashed circle represents the smallest object BactoBox® counts.

Does BacTotal-10 count autoclaved bacteria as cells?

Autoclave treatment causes most bacteria to disintegrate to debris. Usually, the debris becomes smaller than the ~0.5 µm limit. The debris is too small to be detected by BactoBox®.

There are a few exceptions to this. For example, thermophilic bacteria and endospores have some tolerance to autoclave processes.

Summary

When cells are autoclaved they mostly disintegrate to tiny pieces that are rarely detectable by BactoBox®.