CLINICAL LAB SCIENEC

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ESSENTIALS OF CLINICAL LABORATORY SCIENCE
Automation in the Chemistry Laboratory
Almost total automation of the clinical chemistry laboratory has now been achieved.
Preanalytical steps have been largely automated through use of robotic or other
mechanical devices to identify samples by bar code and enter prescribed workloads
into the LIS, which in turn generates identification labels for each sample.
The prompt delivery and safe handling of infectious specimens may require
protective transportation techniques and containers to ensure personnel safety.
Traditionally, specimens are delivered to the laboratory by human transporters
and, in some facilities, by a pneumatic tube system. In some areas, robotic tracking
and transport systems are available that transport samples from the receiving area
to the correct laboratory department. More advanced systems identify the sample,
program the analyzers, and even centrifuge the samples to provide serum or
plasma for testing. Total automation is designed primarily for larger laboratories
as it not feasible or cost effective for smaller laboratories. Commercial laboratories
that complete tens of thousands of tests per day all use fully automated systems.
The miniaturization of analyzers has paralleled that of computers. Ionselective
electrodes that are extremely small and perform procedures almost
instantaneously are being used for a number of procedures, and others are on the
way. Smaller electronic components with microchips use electrophoresis to perform
minute separations of proteins into their divisions based on size and weight.
Nanotechnology is a term used to describe the manipulation of materials that are
extremely small and are measured in nanograms (billionths of a gram), such as
atoms or molecules, including biochemical components like hormones that are
found at very small levels in the human body.
Significance of Specimen Preparation and Testing
Chemistry procedures available for treating diseases or assessing health are many
and varied. The sample collection process for chemistry is the first and most important
step in performing clinical chemistry tests. Subtle changes or errors in collection
will invalidate the results of many procedures, causing delays in treatment
or perhaps administration of the wrong treatment. There are also many different
types of specimens that are required for certain analyses. Some instruments require
a particular type of specimen, such as plasma using only heparin as an anticoagulant
(a substance to prevent clotting), although there are several other anticoagulants.
Others may accept whole blood, plasma, serum, capillary blood, and other
body fluids. When drawing lists are provided for specimen collection, the type of
tube and any anticoagulant required will sometimes be specified to avoid errors
leading to erroneous results from preanalytical error (mistakes that occur through
mishandling or misidentification of a sample). Remember also that arterial blood
is used for blood gases but not for other analyses.
A quick review of specimen requirements for chemistry analysis, covered
previously in the phlebotomy section, follows:
1. Specimens must be properly identified according to standard procedures
followed by the facility.
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