The investigator may find it beneficial to empirically determine the most appropriate extraction technique for the assay sensitivity desired. Alternatively ATP can be extracted by treating the sample with perchloric acid. The perchlorate supernatant must be neutralized prior to assay. The detection limit may be extended to 10 -15 moles ATP with the addition of luciferin at a concentration of approximately 1 millimolar. Arsenate, an endogenous component of Firefly Lantern Extracts, is particularly inhibitory to the bioluminescent reaction.
Sensitivity is increased when arsenate is removed.
Zero the instrument employed. Firefly Lantern Extract Solution prepared in Step 1 into an appropriate tube or cuvet. Place tube in instrument and record the intensity of the background light emitted. Pipet into the tube 20 uL of the sample. Immediately start timer.