Proteinase K question

[grandhotel]

Hi

Basically I am preparing a PCR mix using drosophila so I could run a gel later, my question is that after I added the "proteinase K" to the fly mixtures the mixture had to be incubated for 30 minutes at 56ºC, what is the reasons the that proteinase K step was carried out at 56ºC?

Thanks in advance

[admin]

Proteinase K is a protease which will degrade proteins. This is to do several things.

1) degrade protein to purify DNA
2) degrade protein DNAses to PREVENT breakdown of your DNA

This (1 & 2) will yield better PCR results

[grandhotel]

Thanks for you answer, but is there a special reason why this step is specifically carried out at 56ºC?

[grandhotel]

Thanks for your reply, but do you know why this step has to be specifically carried out at 56ºC?

[admin]

This is most probably the best temperature for Proteinase K enzyme activity, and/or possibly for slightly reduced DNase activity.

I would look up the optimal temperatures for enzyme activity for both