Gel extraction kit

Discussion of all aspects of biological molecules, biochemical processes and laboratory procedures in the field.

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
samkh918
Garter
Garter
Posts: 20
Joined: Thu May 01, 2008 9:27 pm

Gel extraction kit

Post by samkh918 » Thu Aug 14, 2008 7:38 pm

Hello,

I was wondering if someone could explain the main purpose of the gel extraction kits. In some protocols I see that after performing PCR on the vector containing gene of interest, the amplicon is run on the gel first and the extracted using gel extraction kits. They then proceed with A-addition, ligation and transformation. Why A-addition is not performed directly on the amplicon? Is it mainly to get pure DNA because there might be impurities in the PCR reaction?! Or is it a double check for the size of amplicon?

Thanks for your help.

snowcapk
Garter
Garter
Posts: 37
Joined: Fri Oct 26, 2007 2:01 am

Post by snowcapk » Thu Aug 14, 2008 9:48 pm

The main purpose of running the fragment on the gel is to remove impurities, like you said: you can cut out the band (assuming there are multiple bands) that contains the fragment you want and extract it from the gel. You should always run a gel of your PCR product anyway to check for impurities and check the size of the amplicon. If the probability of non-specific products is high, running the whole PCR product on a gel to begin with and extracting it afterwards will save you time and frustration. The cost is comparable because you would need to clean up your PCR reaction before A-addition if you don't do a gel extraction, but you don't need to clean up your PCR product before running it on a gel (the bands will be a little blurry though).

Post Reply

Who is online

Users browsing this forum: No registered users and 11 guests