about running electrophoresis... why?

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

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
luckygirl
Garter
Garter
Posts: 1
Joined: Mon Jul 02, 2007 2:47 am

about running electrophoresis... why?

Post by luckygirl » Mon Aug 13, 2007 7:33 am

the first time that I run electrophoresis, there is no srand in it, who can tell me why?
thank you very much.

User avatar
canalon
Inland Taipan
Inland Taipan
Posts: 3909
Joined: Thu Feb 03, 2005 2:46 pm
Location: Canada

Post by canalon » Mon Aug 13, 2007 3:33 pm

No DNA you mean?
Do you have a molecular weight marker? If it shows, that is a sample problem, otherwise, it is likely a staining problem. Or maybe you run your gel too long. i cannot really help more without details.
Patrick

Science has proof without any certainty. Creationists have certainty without
any proof. (Ashley Montague)

molecular newbie
Garter
Garter
Posts: 14
Joined: Tue Jun 27, 2006 7:12 pm

No DNA? No ethidium?....

Post by molecular newbie » Mon Aug 13, 2007 7:27 pm

Well assuming you were running DNA electrophoresis in an agarose gel, there could be many reasons why you dont see a band.

1) Your PCR might not have worked. The primers or polymerase could have been bad thus leading to a lack of PCR product. This is probably unlikely if your DNA to begin with was good.

2) Another problem could be staining. Did u add ethidium bromide to the gel before it set? If so , try adding it to the buffer as it runs. Also make sure u mix the PCR product with the blue marker before loading the sample into the well.

3) Most likely the DNA was no good to begin with and thats why there was no PCR product. Did u extract the DNA yourself?

4) one other unlikley reason might be that u ran the gel to long and the DNA band ran off the gel.

Hope this helps. Good luck.

User avatar
mith
Inland Taipan
Inland Taipan
Posts: 5345
Joined: Thu Jan 20, 2005 8:14 pm
Location: Nashville, TN
Contact:

Post by mith » Mon Aug 13, 2007 11:04 pm

We use a ladder to test.
Living one day at a time;
Enjoying one moment at a time;
Accepting hardships as the pathway to peace;
~Niebuhr

Post Reply

Who is online

Users browsing this forum: No registered users and 5 guests