Login

Join for Free!
118288 members


PCR to screen for diseases

Genetics as it applies to evolution, molecular biology, and medical aspects.

Moderator: BioTeam

PCR to screen for diseases

Postby james86 » Sat Mar 20, 2010 12:50 pm

My notes mention several times how some genetic disorders can be screened via PCR, and differentiate this technique from Southern blotting. What is the difference between these techniques; I simply thought pcr involved amplification of dna?
james86
Garter
Garter
 
Posts: 3
Joined: Sat Mar 20, 2010 11:33 am

Postby JackBean » Sat Mar 20, 2010 5:06 pm

I think, they are pretty different. Yes, PCR involves amplification of DNA
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5678
Joined: Mon Sep 14, 2009 7:12 pm

Postby sunghoo » Sat Mar 20, 2010 5:26 pm

Yes you are right, but it does not simply amplify a piece of dna, in fact, it can also copy the dna . The copies can be studied or used in comparison with other original DNA samples which in return you can determine if the dna sequencing is correctly represented, and possibly, genetic disorders can show up.
Difference between the two is that PCR uses extracted bacteria called "Taq polymerase", where as southern blotting uses probe which is single-stranded DNA to indicate the sequences.
sunghoo
Garter
Garter
 
Posts: 28
Joined: Sat Mar 20, 2010 4:47 pm


Re:

Postby JackBean » Sat Mar 20, 2010 5:55 pm

sunghoo wrote:Yes you are right, but it does not simply amplify a piece of dna, in fact, it can also copy the dna .

and what is amplification?

There are plenty of Pol for PCR, some are derived from TaqPol, but many aren't.
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5678
Joined: Mon Sep 14, 2009 7:12 pm

Postby sunghoo » Sat Mar 20, 2010 6:29 pm

what do you mean what is amplification?
sunghoo
Garter
Garter
 
Posts: 28
Joined: Sat Mar 20, 2010 4:47 pm

Re: Re:

Postby JackBean » Sat Mar 20, 2010 8:00 pm

sunghoo wrote:but it does not simply amplify a piece of dna, in fact, it can also copy the dna .

you wrote, that it does not only amplify, but also copy the DNA. So, what's the difference?
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5678
Joined: Mon Sep 14, 2009 7:12 pm

Postby sunghoo » Sat Mar 20, 2010 8:08 pm

amplification is not same as copying dna, amplification means to enlarge or make it better, where as copying means just to make another clone of dna........
sunghoo
Garter
Garter
 
Posts: 28
Joined: Sat Mar 20, 2010 4:47 pm

Postby JackBean » Sat Mar 20, 2010 9:03 pm

well, if you amplify some piece of DNA, you make a copy, don't you?
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5678
Joined: Mon Sep 14, 2009 7:12 pm

Postby sunghoo » Sat Mar 20, 2010 10:37 pm

Right. haha I forgot about that
sunghoo
Garter
Garter
 
Posts: 28
Joined: Sat Mar 20, 2010 4:47 pm

Postby james86 » Sun Mar 21, 2010 1:45 pm

Thanks alot for the replies. so having amplified the DNA, how would you screen for the genetic disorders if not via southern blotting?

Thanks
james86
Garter
Garter
 
Posts: 3
Joined: Sat Mar 20, 2010 11:33 am

Postby JackBean » Sun Mar 21, 2010 1:54 pm

that depends on what type of mutation you have. If some large indel, you can look to gel and see the size of your amplicon. If you have some 1 nt mutations (indels, exchanges), the best way is to discriminate between present/absent (you design one of your primers to the mutation. This is how are SNP examined)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.
User avatar
JackBean
Inland Taipan
Inland Taipan
 
Posts: 5678
Joined: Mon Sep 14, 2009 7:12 pm

Postby debabio » Tue Apr 20, 2010 2:25 pm

For diagnosis 1st you have to design a primer n amplify the sequence, the amplified DNA is then sequenced and the sequence is then compared to the data base of known sequence to determine wheather it is normal or mutant,example- Sickle cell anemia, thalassemia etc.
debabio
Garter
Garter
 
Posts: 1
Joined: Mon Apr 19, 2010 7:00 pm

Next

Return to Genetics

Who is online

Users browsing this forum: No registered users and 2 guests