Library Screening

Chi-kuang Wen ckwen at
Mon Dec 16 13:45:59 EST 1996

Rajesh Kumar (rk6n at VIRGINIA.EDU) wrote:

: Hi Netters,

: I am screening a genomic library made up in lambda ZapII vector. I want to
: know the growth conditions so as to get 20 000 plaques per 150mm plate.
: Right now I am following Maniatis (NZY plates, plaques are grown for 12h
: at 37C), but I do not get more than 2 000 plaques (almost touching each
: other) per plate. The size of my plaques is almost equal to a well grown
: bacterial colony.
: Any suggestions in this regard will be appreciated. 

Dear Rajesh:

First, you may want to check the titer of your library.
Also, the bacterial strains might be important for some genomic DNA which
contains hyper-methylated DNA.  If the strains were not right, then you 
won't get a good titer.
Third, plating the phages is important, if your top agarose partially solidifies, your titer will be  highly reduced. To check this, just see if the top agar
is smooth after it's solidified.

hope this help,


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