I am currently looking at the EROD activity in earthworm microsomes, I have tried using calcium chloride aggregate extraction as I do not have access to an ultracentrifuge. However the resulting pellet from the calcium aggregate method is almost non existent. I went ahead using that very little pellet to quantify the EROD activity in the HPLC using the uv detector with absolutely no peaks forming. Does anyone have any idea how I can successfully extract microsomes without ultracentrifuge and how to quantify EROD?