Selective PCR amplification

[brett]

>We are trying to clone several closely related sequences via PCR 
>using the same primers. The products are different sizes, from 300 to 
>600 bp. When we amplify and clone, we have to screen many recombinant 
>before we can find the smaller ones. Is it possible to control the PCR 
>conditions e.g., by lowering the time of extension, in order to selectively 
>amplify the smaller products?
>
>Any suggestions greatfully considered.
>
>Doug Johnson
>Dr. D.A. Johnson
>Plant Molecular Biology
>Department of Biology
>University of Ottawa
>30 Marie Curie
>Ottawa, Ontario
>K1N 6N5
>1-613-562-5800 ext 6347
>1-613-562-5486(FAX)

Not really. You could modulate annealling conditions to better amplify the
copies that exactly match your primers. Additionally, I recommend cloning
products which have been sized on a gel.


Brett Lindenbach
    
Program in Immunology                              
Washington University - St Louis                  
brett at borcim.wustl.edu                             

"I own my own pet virus. I get to pet and name her." - Cobain