Dear all,

I am trying to determine starch content in algae samples using the protocol described in Brányiková et al., 2011 (Biotechnol. Bioeng. 108(4):766-776), which involves pigments extraction with ethanol followed by perchloric acid treatment. My problem is that I cannot really resuspend in perchloric acid the insoluble material remaining after ethanol extraction. What I am obtaining are bigger or smaller particles, and this is a big constraint to mu view as extraction efficiency can vary a lot depending on particle size (the bigger, the worse). I am thinking about sonicating samples. If someone has experience with this protocol, I would be very grateful for any useful advice to improve methodology and ensure reliability of results.

Thanks a lot in advance.