Sciencemadness Discussion Board

Amino acid detection with o-Phthalaldehyde

zinc finger - 6-10-2021 at 00:51

Hi there,

I just found a bottle of o-Phthalaldehyde in the lab.
It is a ready to use solution and I just added some alanine but nothing happened. Any idea what could have went wrong?
The bottle was pretty much full and the reagent only show a very slight yellow tint.

opa.jpg - 2.2MB

Texium - 6-10-2021 at 05:38

It’s a fluorometric indicator. I wouldn’t expect to see a visible change.

karlos³ - 6-10-2021 at 15:25

You "added" the alanine?
I hope not into the bottle? :o

zinc finger - 12-10-2021 at 08:13

Sorry for my late reply

@Texium Why not? The achievable fluorescence intensity should be relatively high. Here they used it to develop TLC plates and visually inspected the results. Or do you think the reagent is to dilute in this mixture and the resulting fluorescence can only be detected with a photometer? Maybe I should add that I inspected them under UV light :)

@karlos³ Did it in a test tube - don't worry :D

Texium - 12-10-2021 at 10:46

It’s probably pretty dilute, and intended to be used with a spectrofluorometer where the concentration needs to be low in order to not overload the detector.