DAHD ultraviolet at
Fri Jun 18 16:32:24 EST 1999

In article <RVT8UAAKtla3EwHV at>, 
Duncan at says...

I did bunches of phage work 35 years ago.  I agree the yield sounds
low by about one order, at least.

HOWEVER-- are you absolutely positive etc. that you have done 
your dilution series calculations correctly.  IT is so easy to lose
a decimal along the way.   FOr example, what volume of lysate are
you adding to the overlay on your last plating?  If less than a ml
have you corrected for that --probably a factor of 10?

I do serial dilutions of one sort or another on an almost daily
basis and almost always have to struggle to check, double check, and
recheck the calculation.  

A handy rule, when off by one log, be suspicious of your dilution
series and calculation.

>Hi Folks,
>Is anyone currently playing with phiX174 or have done so in that past?
>I'm trying to find out what no. of phage are released per infected 
>I'm using the am3 cs70 phage with the appropriate E.coli C suppressor
>and non-suppressor hosts and am not sure what titre I should get. 
>I'm getting roughly 10E11 phage in total from a 100ml suppressor 
>but from hand-written notes I have from elsewhere, that seems low. 
>Revertant phage (i.e. to wild type) are at least 10E6 down on the
>Many thanks
>The problem with being on the cutting edge is that you occasionally get 
>sliced from time to time....
>Duncan Clark
>DNAmp Ltd.
>Tel: +44(0)1252376288
>FAX: +44(0)8701640382

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