An automated analyser is a medical laboratory instrument designed to measure different chemicals and other characteristics in a number of biological samples quickly,with minimal human assistance.

These measured properties of blood and other fluids may be useful in the diagnosis of disease.

Many methods of introducing samples into the analyser have been invented.This can involve placing test tubes of sample into racks,which can be moved along a track,or inserting tubes into circular carousels that rotate to make the sample available.Some analysers require samples to be transferred to sample cups.However,the effort to protect the health and safety of laboratory staff has prompted many manufacturers to develop analysers that feature closed tube sampling,preventing workers from direct exposure to samples.,

Samples can be processed singly,in batches,or continuously.

The automation of laboratory testing does not remove the need for human expertise (results must still be evaluated by medical technologists and other qualified clinical laboratory professionals),but it does ease concerns about error reduction,staffing concerns,and safety.

Routine biochemistry analysers

These are machines that process a large portion of the samples going into a hospital or private medical laboratory.Automation of the testing process has reduced testing time for many analytes from days to minutes.The history of discrete sample analysis for the clinical laboratory began with the introduction of the "Robot Chemist" invented by Hans Baruch and introduced commercially in 1959.

AutoAnalyzer is an automated analyzer using a special flow technique named "continuous flow analysis (CFA)",invented in 1957 by Leonard Skeggs,PhD and first made by the Technicon Corporation.The first applications were for clinical (medical) analysis.The AutoAnalyzer profoundly changed the character of the chemical testing laboratory by allowing significant increases in the numbers of samples that could be processed.The design based on separating a continuously flowing stream with air bubbles largely reduced slow,clumsy,and error prone manual methods of analysis.

The types of tests required include enzyme levels (such as many of the liver function tests),ion levels (e.g.sodium and potassium,and other tell-tale chemicals (such as glucose,serum albumin,or creatinine).

Simple ions are often measured with ion selective electrodes,which let one type of ion through,and measure voltage differences.Enzymes may be measured by the rate they change one coloured substance to another; in these tests,the results for enzymes are given as an activity,not as a concentration of the enzyme.Other tests use colorimetric changes to determine the concentration of the chemical in question.Turbidity may also be measured.

Immuno-based analysers
Antibodies are used by some analysers to detect many substances by immunoassay and other reactions that employ the use of antibody-antigen reactions.

When concentration of these compounds is too low to cause a measurable increase in turbidity when bound to antibody,more specialised methods must be used.

Recent developments include automation for the immunohaematology lab,also known as transfusion medicine.