Rafael Andres Garcia

6 Questions 10 Answers 0 Followers

Questions related from Rafael Andres Garcia

Which amino acid side chains does OPA (o-phthaldialdehyde) react with?

I know it reacts with the alpha-amino group, but I'm only interested in the side chains. I think it reacts with lysine, but what about glutamine or asparagine?

22 November 2017 5,301 3 View

How can I deamidate glutamine and asparagine residues in protein, but leave the protein otherwise intact?

I don't care if the protein conformation or biological activity is lost. I just want to change Asn and Gln to Asp and Glu. I do want to avoid proteolysis.

07 July 2017 9,258 3 View

Is there a word for the liquid remaining after a substance has precipitated out (analogous to supernatant, raffinate, filtrate)?

Is supernatant correct? I've only every used that word in the context of centrifugation.

22 February 2017 2,064 1 View

Is it really necessary create a new calibration curve each day for spectrophotometric assays?

I have always been taught to do this, but without any explanation of the reason. Does the instrument response really vary that much from day to day, given that you allow the lamp adequate time to...

01 February 2016 1,291 12 View

What is the best resistivity you get from your laboratory ultrapure water system?

The theoretical maximum for water at 25C is 18.18 MOhm-cm. When it was brand new, my water system could produce water that was this clean. These days, even after complete maintenance of the system...

05 June 2015 9,304 3 View

Why do the heme and the protein components of hemoglobin dissociate at low pH?

07 January 2015 3,449 0 View