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Does adenine incorporation into nucleic acids measure total microbial production:: a response to comments by Fuhrman et al

Journal Article · · Limnol. Oceanogr.; (United States)

The uptake and incorporation of (/sup 3/H)adenine as a measure of total microbial (bacteria and unicellular algae) nucleic acid synthesis depends on the validity of several assumptions. A unique characteristic of the (/sup 3/H)adenine method is the ability to measure the specific radioactivity (nCi pmol/sup -1/) of the immediate precursor pool of the adenine incorporated into nucleic acids. This measurement permits correction for isotope dilution when the added radiotracer mixes with exogenous pools of structurally related compounds before uptake and with endogenous pools after transport into the cells. The immediate precursors to (/sup 3/H)adenine incorporation into cellular RNA and DNA are ATP and dATP. Since the intracellular dATP pool is in isotopic equilibrium with the ATP pool, one can determine the specific radioactivity of both precursor pools by measuring that of the intracellular ATP pool. If the specific activity of the precursor pool is not measured, then it is impossible to extrapolate incorporation measurements to estimates of nucleic acid synthesis with any degree of accuracy.

Research Organization:
Univ. of Hawaii, Honolulu
OSTI ID:
6479287
Journal Information:
Limnol. Oceanogr.; (United States), Journal Name: Limnol. Oceanogr.; (United States) Vol. 31:6; ISSN LIOCA
Country of Publication:
United States
Language:
English