Patent ID: 7416896

Claim:
A method for determining total bilirubin in plasma, the method comprising the steps of: (a) disposing a sample of plasma in a first reservoir; (b) disposing a first reagent in a second reservoir; (c) disposing a second reagent in a third reservoir; (d) connecting the first, second, and third reservoirs to a selection valve; (e) using the selection valve to dispose a first air zone in a holding coil; (f) using the selection valve to dispose a liquid zone in the holding coil by withdrawing, under conditions of fluid flow, portions of the first and second reagents from the second and third reservoirs, respectively, and of the sample from the first reservoir, and mixing the portions of the first and second reagents and of the sample in the holding coil; (g) using the selection valve to dispose a second air zone in the holding coil, thereby disposing the liquid zone between the first and second air zones, and forming a zone stack comprising the first air zone, the liquid zone, and the second air zone; (h) passing the zone stack by a detector; and (i) using the detector to generate a signal indicative of concentration of total bilirubin in the sample.