Blood Collection and Preservation
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2.1 Blood Collection
Blood is a bodyfluid containing plasma, red blood cells (RBCs), white blood cells,
and platelets. Blood is specialized for performing various functions such as transport
of nutrients and oxygen to various body organs, transportation of antibodies, trans-
port of waste products to kidneys, and regulation of body temperature. Normally,
blood pH is maintained in narrow range of 7.35–7.45. Blood for biochemical
investigations may be drawn from arteries, veins, or capillaries. Venous blood is
commonly used for majority of biochemical investigations. It can be drawn from any
prominent vein. Arterial blood is mostly used for blood gas analysis. Radial,
brachial, or femoral arteries are the most common site for arterial blood. Capillary
blood is collected by puncture in infants or when very little blood is required. Blood
is collected in various collection tubes called vacutainers which are sterile glass
tubes with a colored rubber stopper. Blood contains various chemical constituents
such as glucose, proteins, lipids, globulin,fibrinogen, urea, amino acids, uric acid,
creatinine, hormones, vitamins, electrolytes, etc. (Fig.2.1).
Hemolysis of Blood Hemolysis is the release of hemoglobin from red blood cells
that give pink to red color to plasma/serum. Hemolysis during sampling, transporta-
tion, and storage should be avoided since it causes changes in measurement of a
number of analytes.
Collection of Specimen Many factors need to be considered when collecting lab
specimen. In some cases, preparation of the patient prior to the test may be required.
The sample volume to be collected depends upon the number and type of tests being
performed. Generally 3–5 ml blood is required for many investigations. If the tests
are run on automated instruments, then less volume of blood may be sufficient.
#Springer Nature Singapore Pte Ltd. 2018
V. Kumar, K. D. Gill,Basic Concepts in Clinical Biochemistry: A Practical Guide,
https://doi.org/10.1007/978-981-10-8186-6_2
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