Calculating DNA Concentrations

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

Moderators: honeev, Leonid, amiradm, BioTeam

Post Reply
skillen
Garter
Garter
Posts: 2
Joined: Sat Nov 28, 2009 12:06 am

Calculating DNA Concentrations

Post by skillen » Sat Nov 28, 2009 2:07 am

Why must you calculate DNA concentrations by only using the dilutions that have a A260 nm value between 0.050 and 1.5? I've done the calculations, but I don't know WHY they need to be done that way. Any help is appreciated.

User avatar
JackBean
Inland Taipan
Inland Taipan
Posts: 5694
Joined: Mon Sep 14, 2009 7:12 pm

Post by JackBean » Sat Nov 28, 2009 12:55 pm

1) if you look at the whole spectra, you will see, that if is absorbance higher than 1, it is not straight line, but more like zigzag, so it's not much accurate ;)
2) absorbance is log of the original light and the light gone through (A = I_0/I). So, imagine, if you have absorbance of 0.05 or 1.5, what part of light actually goes through? It is either more than 90% or less than 10% (in the case of 0.1 and 1, respectivelly, calculate real numbers for you case), so this is not much accurate either ;)
http://www.biolib.cz/en/main/

Cis or trans? That's what matters.

skillen
Garter
Garter
Posts: 2
Joined: Sat Nov 28, 2009 12:06 am

Post by skillen » Sat Nov 28, 2009 5:42 pm

Thanks very much for the help!

Post Reply

Who is online

Users browsing this forum: No registered users and 3 guests