CLINICAL LAB SCIENEC

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ESSENTIALS OF CLINICAL LABORATORY SCIENCE
Serum and Plasma as Clinical Specimens
What is the difference between serum and plasma? A blood tube that contains
no anticoagulant may have clot enhancers as well as barrier materials to separate
blood cells and platelets from the liquid portion of the blood. When the blood
is allowed to clot and is then centrifuged, the resulting liquid portion of the
blood that overlays the cells is called serum. The barrier gel will move to an area
between the cells and the serum, allowing easy separation. Blood collected in a
tube containing an anticoagulant will not clot if the blood and anticoagulant are
in the proper ratio to each other. When an anticoagulated sample is centrifuged,
plasma results when the cells and liquid portion are separated. The plasma contains
coagulation factors that are absent in serum, which is obtained after the
blood has clotted, a process that uses up most of the coagulation factors.
Clnical Chemistry Procedures
The following representative laboratory procedures for chemistry determinations
demonstrate a variety of manual procedures for several different analytes
and for each of the five major departments of the laboratory. For some chemistry
procedures, the results will correlate with and confirm the results from other
departments. The manual chemistry procedures presented here can be performed
with a minimum of equipment and supplies. Basic knowledge of each of these
procedures will be valuable to the student of medical laboratory technology as
a preparation for working at a clinical site. Even though most clinical sites will
perform most of their procedures on automated equipment, there are strong
correlations between the manual and automated processes.
Some instructors may wish to have students perform some of these procedures
as an introduction to the performance of more comprehensive laboratory procedures
in other courses. Programs are often designed where both theory and practice may
be taught in specific courses related to each of the major laboratory areas. However,
in some medical laboratory programs, the practical portion of your education may
be deferred until you are assigned to a clinical site such as a hospital laboratory.
In the Lab
BASIC CLINICAL CHEMISTRY PROCEDURES
MANUAL CHEMISTRY PROCEDURE #1
Total Protein
Principles
Abnormal total protein values are most often related to liver disease. Although
proteins are found in all body fluids to varying degrees, serum is the best fluid for
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