mantei at neuro.biol.ethz.ch (Ned Mantei) writes:
>doerner at papin.HRZ.Uni-Marburg.DE (Doerner Wolfgang) wrote:
>> anyone out there who knows what a Klett-Unit is?
>I used a Klett spectrophotometer as a student in the 1960's, and even then
>had the impression that the instrument was an old design (1940's?). The
>absorbance was indeed measured in "Klett units", but I don't know how many
>correspond to an O.D. unit.
The Klett was basically a value for light-scattering by bacterial suspensions.
You will not be able to convert to OD600 or to cell density (cfu/mL) with
any reliability (as all these measures are strain ependent, as so often noted
in similar discussions in this newsgroup). When it comes to that, OD600 is
only a light-scattering measure too, so sneer not at the humble Klett.
On the instrument I was raised on, Klett 40 was early log, 100 about mid-log
and growth normally plateaued at around 350. For coli (a K12 derivative).
Wouldn't like to bet this is the same for all Klett machines or strains.