I'm looking for the most sensitive ATP assays. Ideally, we'd like to be able to detect around 1 amol ATP/well, but the most sensitive assays we have found are the "HS" assays from Biothema (for example, ATP Biomass HS), which are rated at 10 amol. They offer also the "ATP Reagent SS", which in theory should reach 1 amol, but it seems to be problematic. And other assays I have found are 10 or even 100 times less sensitive than the HS assays.

Does anybody know any ATP assay that can quantify 1 amol ATP/well?