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Borrelia help - Enumerating spirochetes (Aug/12/2008 )

Hi folks,
I'm growing spirochetes (Borrelia) in liquid media and need to enumerate how many are in my culture tubes. I don't have a darkfield hemocytometer but I have a regular one. Does anyone have a procedure on counting these bugs? Thanks much!

-bkc-

here's one

Quantitation of spirochetes in vitro. Quantitation of the spirochetes grown in vitro was performed as follows. Cultures were spun down and washed twice with phosphate-buffered saline (PBS). The spirochetes were resuspended in PBS, and the absorbance at 600 nm was determined. The absorbance at 600 nm was shown in parallel experiments to correlate with the number of spirochetes, as counted by dark-field microscopy, in a linear manner. One unit of absorbance at 600 nm was determined to equal 1.9 × 109 spirochetes/ml.

-jorge1907-