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Urine is one of the most easily obtained specimens examined in the
laboratory, and examination of the urine not only provides information about
the functioning of the kidneys and possible abnormalities of the urinary tract,
but may also lead to the diagnosis of various systemic diseases of the human
body which are reflected by the presence of several substances in the urine.
 Collection of specimen
 Early
morning urine
This is the best urine specimen for routine analysis and
is collected soon after the patient awakens. It is usually concentrated and
has an acid pH. Casts and cells are poorly preserved in dilute or alkaline
urine and traces of dissolved substances such as protein and sugar can be
missed if the urine is very dilute.
Random
urine
This specimen is collected at any time and is convenient
for the patient and is suitable for most screening purposes.
Preservative
used
For routine analysis, no preservative is required but
the urine is best examined fresh. Bacterial growth will ruin a specimen if
analysis is delayed for more than 3 hours. Refrigeration is the best way to
preserve it if analysis is delayed. Refrigeration for more than 24 hours isnot recommended.
Container
for urine collection
The container used must be thoroughly clean and free
from any detergent or disinfectant residue since the oxidants contained in
such cleaning agents may cause the test areas for glucose and blood to
indicate false positive results. After the urine is collected, the container
should preferably be sealed.
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