Tsiry Rasamiravaka Author Answered Jun 8, 2018
Laboratoire de Biotechnologie Végétale, Université Libre de Bruxelles, Belgium
Dear Liao,
Thank you very much for your interest to this protocole, and thank you very much for testing the protocol at lower concentration. It's indeed interesting to notice that pink color.
The maximum absorbance peak may vary according to the purety of the methylene blue used so in your case the max absorbance peak is 650nm. The pink color may be also due to the chloroform used (technical grade, analytic grade or HPLC grade) so use
the 0µg/ml as a blank.
I suggest you to do the absorbance measurement at different Absorbance from 560nm to 660nm (with 20 nm steps), and for 100µg/ml to do a dilution before measurement.
Then you can find the best absorbance that generate the best linear curve for you.
Regards
Tsiry