Petroff-Hausser chambers

Petroff-Hausser chambers may be purchased from Electron Microscopy Sciences, Hatfield, PA. 

Grow B. burgdorferi cultures to mid- to late-exponential phase (approximately 5-9 X 10 cells/mL as determined by darkfield microscopy using a Petroff-Hausser chamber) (see Note 3). Usually a 100 mL culture provides sufficient cell numbers for about two transformations. 

After overnight recovery, enumerate B. burgdorferi cells using a Petroff-Hausser chamber and plate in solid BSK medium with appropriate antibiotic selection. Subsurface colonies develop in 6-10 days, depending on the strain. 

Petroff-Hausser counting chamber, for use primarily with bacteria. Both chambers have a special square grid marked on the surface of... 

Determine the number of Y. pestis per mL by direct count, using a Petroff-Hausser bacterial counting chamber and a phase-contrast microscope (400x magnification). 

Microorganisms Cell numbers Specific organisms Microscopic examination Cell numbers are obtained with a Petroff-Hausser counting chamber. Fluorescent dyes can light up specific microbes. Requires a microscope with high magnification, phase contrast, and ultraviolet fluorescence, as appropriate. Cell counts are straightforward, but particulates and fluorescent materials may interfere. 

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