FISHER, THOMAS R., JR., EVELYN B. HAINES, AND RICHARD J. VOLK. A comment on the calculation of atom

593595 of A comment of atom for We = [W]CO, - We 1 76-82084 593 t: time, incubation some after value T.R.F. to OCE grant NSF by Supported final a and zero” “time a from obtained is this Typically, time. over excess % atom ignored. be not should it 13C of increase of rate the from calculated paper technique a in because it note are h-l) = (units rates turnover Carbon %. atom of calculations affect greatly not denominator. the in appears should but calculation, P3C for portant a, because incorrect also is equation This im- is correction minor is Th 1957). (Craig 1. Eq. their from obtained is a, where abundances lzC and 13C of calculation a1 loo x + [‘3C]CO, precise for applied be must which ple [13c]co, sam- CO, the in 170 of abundance the for da,ldt correction a is There expression. 613C the in 12C and 13C of abundances the for 44 below: reproduced also is (VJ, rates over and 45 of intensities signal mass of tution turn- carbon calculate to used they which substi- improper of because proximation (1977), al. et Slawyk of 2 Equation ap- an only is It 613C/10. approximates below. “al” of value their then replaced, are ets discussed as value, % atom unenriched brack- omitted the If 13C. excess % atom an of instead used often is value % atom or P3C either calculate to used be cannot time-zero a practice in However, period. al. et Slawyk of 1 Eq. written, As 1971). incubation the of end the at and [13C]C02 Epstein and Smith 1953; Craig (e.g. ...