P RINCIPLES OF C LINICAL C HEMISTRY A UTOMATION

A UTOMATION I N C LINICAL C HEMISTRY The modern clinical chemistry laboratory uses a high degree of automation. Many steps in the analytic process that were previously performed manually can now be performed automatically. This Permits the operator to focus on tasks that cannot be readily automated and increasing both efficiency and capacity.

A UTOMATION I N C LINICAL C HEMISTRY The analytic process can be divided into three major phases— preanalytic, analytic, and postanalytic— corresponding to sample processing, c hemical analysis, and data management, respectively. Substantial improvements have occurred in all three areas during the past decade. The analytic phase is the most automated.

W HY A UTOMATION ? Increase the number of tests by one person in a given period of time. Minimize the variations in results from one person to another. Minimize errors found in manual analyses – equipment variations – pipettes. Use less sample and reagent for each test

T YPES O F A NALYZERS Continuous Flow Tubing flow of reagents and patients samples Centrifugal Analyzers Centrifuge force to mix sample and reagents Discrete Separate testing cuvettes for each test and sample Random and/or irregular access

Continuous Flow Analyzers ( nearly out of date) Liquids are pumped through a system of continuous tubing. Sequential analysis in which all samples pass through the same continuous stream and undergo the same analytical process at the same rate.

samples were aspirated into tubing to introduce samples into a sample holder. bring in reagent, create a chemical reaction,. then pump the chromagen solution into a flow-through cuvette for spectrophotometric analysis. Continuous flow analyzers

CENTRIFUGAL ANALYZER In this type of analyzer, the sample and the reagents are placed in separate wells, which are oriented radially around a circular transfer disk. As the centrifuge spins, the centrifugal force pulls the sample and the reagents into the cuvette where mixing occurs. A single optical source and detector, located below and above the transfer disk’s outer edge, measures the absorbance each time the cuvette passes through the optical beam.

D ISCRETE ANALYZERS Discrete analysis is the separation of each sample and accompanying reagents in a separate container. Discrete analyzers have the capability of running multiple tests on one sample at a time or multiple samples one test at a time. E.g: sample 1 glucose, urea, creatinineand electrolytes sample 2 total protein, albumin, calcium sample 3 triglycerides, cholesterol sample 4 bilirubin, ALT, AST, ALP They are the most popular and versatile analyzers and have almost completely replaced continuous-flow and centrifugal analyzers.

D ISCRETE A NALYZERS Sample reactions are kept discrete through the use of separate reaction cuvettes, cells, or wells that are disposed of following chemical analysis. This keeps sample and reaction carryover to a minimum but increases the cost per test due to disposable products.

UDI LIPSE C HEMISTRY A NALYZER

W ITH AUTOMATION THERE IS STILL SOME VERY BASIC STEPS Specimen preparation and Identification Labeling still critical Programming of instrument Laboratory personnel must perform and observe: Quality Assurance Quality Control