E.coli transformation protocol

[S. LaBonne]

In article <1994Aug22.102122.1 at rand>,  <mccallo at rand> wrote:
>I find it hard to believe that an OD600 of 1.0 is "too late" when 0.94-0.95 is
>your target.  There must be at least that much variation between any two
>spectrophotometers/colorimeters.  
>
>Owen McCall
>Abbott Laboratories
The problem here may be that typical specs are simply not designed
to measure light scattering accurately, and can become non-linear
at surprisingly low apparent OD's (so you could be "stuck" at 1.0 over 
a wide range of actual cell densities).  I use a good old Gilford and
find it starts to have problems above about 0.5, so I dilute any
culture more dense than that if the OD is critical.  BTW I hadn't
heard about this new transformation trick and I'm eager to try it!

-- 
Steve LaBonne                      (labonnes at csc.albany.edu)
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POSITIVE, adj.  Mistaken at the top of one's voice.  -Bierce