How many E. coli = 1 O.D. unit? - (Jan/02/2008 )

Dear my friends,
happy new year!
could any one tells How many E. coli = 1 O.D. unit?
Best wishes [color="#0000FF"][/color]

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Well, I never calculated it.
But it's easy to figure out if you have some LB and time: Just inoculate 100 ul bacteria culture in 4 ml LB and incubate over night (8 hours). Measure the OD value, it should be at least 1.0. Dilute it to be 1.0 and count the E. coli under a microscope.
Haha.

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Hi,
doing viable counts at O.D. points as the culture grows would be better, but my question if you have certain equation to get accurate count relative to OD?
thanks

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I asked the vary same question sometime ago.

Here is the link

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Construct a standard curve of OD V cfu/ml and then the equation of your line can be used to quickly compute how much bacteria you have at a given OD

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A laboratory Manual" says OD (600) of 1 is approx 5x10^8 to 1x10^9 cells/ml in LB or other rich medium. that's right

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