I am planning to measure ATP content of sperm cells from birds and rodents. I will prepare cell lysates and extract ATP using either cold acid or boiling buffer. The common assay technique appears to be the bioluminescence assay. I do not, however, have access to a plate reader with luminescence capabilities. Therefore I was hoping to use the newer colorimetric assays for ATP detection. Can anyone comment on the advantages/disadvantages of these two techniques or offer a reason why the colorimetric assay is not a good approach.