Standard Curve for OD Turbidity vs Cell density - (Oct/05/2009 )

Hello all,

My lab supervisor presented me with a question, assuming I have obtained a good standard curve for a bacterium, when would I need to generate a new standard curve?

I cannot find out the answer...when the bacterium mutates? any ideas?

Thank you in advance!
ydogyy1

When you change growth media, when u change the growth temperature,

or when u obtain a new batch of the same media

any significant parameter change would require a new standard curve .

or if you're using another spectrophotometer.

many things to be listed ..haha

hanming86 on Oct 5 2009, 09:32 PM said:

ohh, yes that makes perfect sense now...changing the conditions, of course!

thank you very much

hanming86 on Oct 6 2009, 03:32 PM said:

Wouldn’t these just require a new growth curve rather than a new standard curve?

DRT on Oct 6 2009, 02:18 PM said:

Yea u're right. i have misunderstood the question.

Change of the spectrophotometer might require a call for a new standard curve though. the rest probably can be discarded.

hanming86 on Oct 6 2009, 06:50 PM said:

ohh, why are the rest discarded?

if the bacteria are grown differently, than isn't it true that we can no longer use the standard curve since they may have grown more/less colonies at a certain turbidity ??

There seems to be some confusion here about what you mean by "standard curve". By "when would I need to generate a new standard curve", do you mean "when would I need to recalibrate the spectrophotometer" or "when would I need to produce a new growth curve of a bacterium under some standard growth conditions"?