3 replies to this topic

[intan]

please help me...

yesterday i extract 5 type of wild microalgae using DNA purification kit...
then i test the DNA template using PCR...
after separate on gel electrophoresis only 2 sample has a band..
then i check the OD of the DNA..
my question is how OD reading related with my template??

[bob1]

OD (presuming you are meaning the absorbance at particular wavelengths, usually A260 and A280) is a measure of the amount of DNA you have in solution.  A measure of the purity can be obtained by the ratio between A260 and A280... pure DNA has a ratio of around 1.8, below this it is contaminated by phenolic compounds and above this there is still salt present and/or RNA.

[intan]

my OD reading give a weird reading...i got ratio around 2.2, 1.16,1.45 and 0.98...
that means my DNA contaminated with others thing right???

[qzlabs]

intan, on 12 July 2011 - 05:35 PM, said:

my OD reading give a weird reading...i got ratio around 2.2, 1.16,1.45 and 0.98...
that means my DNA contaminated with others thing right???

It could also happen when OD reading is too low. You probably did not have enough DNA in your sample. You need more starting culture. If you have problems to make enough culture, please check out our new photo-bioreactors at https://qizhonglabs.com/. They can help you to grow more algae.