摘要 |
An instrument (50) automatically determines the concentrations of HDL cholesterol, LDL cholesterol, total cholesterol and triglycerides for a sample (80) of whole, anticoagulated blood placed in a doughnut shaped container (10). The sample (80) is first separated into its blood cell and plasma (84) constituents using high speed centrifugation (54) and a thixotropic gel (82). Part of the plasma (84) is then deposited in an HDL separation chamber (14) where LDL cholesterol and VLDL cholesterol are precipitated by a reagent and the precipitant is sedimented by high speed centrifugation (54) against V-shaped grooves (40) in the outermost wall (38) of the HDL separation chamber (14). Part of the plasma (84) is diluted ten-fold. The supernatant in the HDL separation chamber is then placed in a cuvette reaction chamber (b 18) where it reacts with a cholesterol reagent. The diluted plasma is placed in two other cuvette reaction chambers (18) where it reacts with chloesterol and triglycerides reagents, respectively. Calibration reagents, stored in storage chambers (20), react in two other cuvette reaction chambers (18) to establish a reference absorbance. A pipettor (58) handles all the fluid transfers in the doughnut shaped container (10) and operates in conjunction with a slow speed motor (56) that precisely moves the spindle (52) on which the doughnut shaped container (10) is mounted. A colorimetric measuring system (70, 72, and 74) monitors the absorbance of chemical reactions occurring in the cuvette chambers (18).
|