Dimitris,

You should check that there is not hemolysis during the extraction process, since otherwise colour compounds or molecules can quench the energy transfer process to photodetectors,  reducing the signal.

Regards

Ramón Fernández

There is huge hemolysis, due to the PBS-Tween buffer I am using....however, I found a reference for selective precipitation of Hb with Butanol:EtOH which precipitates a lot.

Comparing signal with controls (not containing extract) I get 50% reduction in signal immediately....which I cant tell if its from degradation or quenching.

Its weird though because I measure other molecules with the same process and I dont get so much quenching.

I really dont know of a way to extract without hemolysis