Quantitation of lactate by a kinetic method with an extended range of linearity and low dependence on experimental variables
| Autor: | H L Pardue, S D Hamilton |
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| Rok vydání: | 1984 |
| Předmět: | |
| Zdroj: | Clinical Chemistry. 30:226-229 |
| ISSN: | 1530-8561 0009-9147 |
| DOI: | 10.1093/clinchem/30.2.226 |
| Popis: | We report conditions and characteristics of a new kinetic method for measuring lactate. Using a multiple linear regression method, we fit data for absorbance and for rate of change of absorbance to a modified rate form of the Michaelis-Menten equation. The principal objective of the fitting process is to compute the total absorbance change, delta A infinity, that would be measured if the reaction were monitored from the point of mixing to equilibrium. For data collected at 1-s intervals from 5 to 200 s, the fitting process gives values of delta A infinity that vary linearly with lactate concentration from 10.6 to 180 mumol/L in the reaction cell after 150-fold dilution of samples. For a range of enzyme activities that produced a 20% change in the initial rate, the regression-kinetic treatment yielded results with no detectable systematic error. The mean within-day CV was 2.1% for an average concentration of 14.4 mmol/L; the day-to-day CV was 5.2% for 3.90 mmol/L. For 25 samples of canine plasma with lactate concentrations from 2 to 26 mmol/L, comparison of results obtained with the regression-kinetic method (y) with results obtained with a commercially available equilibrium method (x) gave a least-squares equation of y = 1.01x - 10 mumol/L. |
| Databáze: | OpenAIRE |
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