Abstract: This invention discloses methods, compositions and kits for the detection of extremely low levels of nucleic acid, cells and cellular material in biological samples. The nucleic acid detection systems utilize either the pyrophosphorolysis reaction catalyzed by various polymerases or nuclease digestion coupled with pyrophosphorylation catalyzed by phosphoribosylpyrophosphate synthetase to produce either deoxyribonucleoside triphosphates or ribonucleoside triphosphates. dNTPs are transformed to ATP by the action of nucleoside diphosphate kinase. The ATP produced by these reactions may be detected by luciferase or NADH based detection systems. If more sensitive detection is required, schemes for the amplification of NTPs and dNTPS are provided. A detection system for cells or cellular material in a sample is provided wherein AMP and a high energy phosphate donor added to a sample are converted to ATP by the action of endogenous enzymes, followed by detection of the ATP.