Beckman Coulter AU640 Chemistry system

The Beckman Coulter AU640 Chemistry system, formerly the Olympus AU640 boasts over 90

assays with a maximum throughput of 800 tests per hour. The AU family of systems are well-regarded, open reagent, high-quality chemistry systems that are considered one of the most popular

chemistry systems on the market, in particular in the US laboratory marketplace. Chemistry

analyzers measure substances within bodily fluids to establish a pattern of abnormalities. The wide

range of tests can be grouped under several categories such as electrolytes, enzymes, blood sugar,

metabolites, thyroids, hormones, lipids, therapeutic drug monitoring, and drugs of abuse monitoring.

This analysis can be conducted on blood (either whole, serum, or plasma), urine, semen, or

cerebrospinal fluids Chemistry analysis begins with the patient sample placed in separate capsules, test

tubes, slides, or sample cups that are transported on a conveyor with sample racks or in a carousel

in a reagent tray. Specimens are sampled and then mixed automatically together with diluents and

reagents in a reaction cuvette. The reagents are pulled from a reagent carousel, which is typically

refrigerated to keep the reagent’s shelf life longer. The reactive cuvette is stored and processed in

the Reaction carousel. The Reaction carousel holds the mixing station (which mixes samples and

reagents) and wash station (which rinses the cuvettes). Dependent on the manufacturer, the cuvette

is either made of glass or plastic, but must be optically clear so that light may pass through without

any intervention from scratches or blemishes. Chemistry analysis is calculated through the absorbance

of the specific wavelengths as light is passed through the specimen. All chemistry analyzers possess

a photometer (either filter photometer or spectrophotometer) that conducts the measurement of the

light absorbance of the specimen, and results are calculated. Filter photometers use glass filters, on

a rotating filter wheel, coated with colored material while spectrophotometers use prisms or gratings,

to isolate these wavelengths from the scanner beam. In both cases, a lamp (typically halogen) is the

light source. Spectrophotometry is a more commonly used method than Filter photometry, which is

currently only used in J&J, Roche Cobas, and Siemens Dimension systems. Spectrophotometry is

used in most other systems including Abbott, Beckman and Roche Hitachi systems. The process to

attain the results from the absorbance tests are classified either as End Point or Kinetic. End point

method incubates the reaction mixture for a predetermined amount of time to reach the end point, or

equilibrium of the reaction. Kinetic method, as the reagents and the sample are mixed, the reaction

is monitored, the rate of change in absorbance is then determined and related to analyte

concentration. As such, Kinetic is a faster method than End Point.