A petition againts ODs

[David Rose]

"Morris F. Manolson" <mm6y+ at andrew.cmu.edu> writes:

>Further to Denys explanation of how measuring yeast (or bacteria)
>cell titers using OD's has to do more with the geometry of each model
>of spectrophotometers and NOTHING to do with the Lambert-Beer Law
>(Preston, R.A., Jone's lab newsletter #1),  I petition all yeast labs
>to just once make a graph of "OD VS ACTUAL cell titer"  and from
>then on just publish cell titers,  NOT ODs. This would be a great 
>service to the yeast community.  

	This is a really good point; in fact, I am surprised anyone would
publish OD's or Kletts.  You can also get really different results with
different cell morphologies, particularly with arrested cells.  The
particular mutant I work on swells a lot when arrested, so that you can
get errors on the order of 5-fold if you just rely on klett (similar to
OD). Similarly, the percentage of unbudded, budded, and large budded cells
can affect kletts.  So be careful out there....
							Dave Rose