Lab 1
Ali Abdulrasool Hussein
Diagnosis of any disease is first done by physical examination by physician and
confirmed by lab diagnostic tests. Lab values are very important in determination
of disease severity, drug doses and in follow up.
Clinical biochemistry:
In this lab the concentration of one or more substances in biological sample of
patient are measured and compared with reference value obtained from healthy
subjects.
Types of samples that are used in testing:
Body fluids: blood, serum, plasma, urine, cerebrospinal fluid (CSF), feces, and
other body fluids or tissues.
Blood Sample: One of three different samples may be used: whole blood, serum,
or plasma.
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Lab 1
Ali Abdulrasool Hussein
1- Whole Blood - Blood flowing freely through the human body. If it is outside
the body and with an anticoagulant and not separated into the liquid portion
& the cells, it is still called whole blood. Example: a CBC requires EDTA
whole blood.
2- Serum - Blood outside of the human body is designed to clot. This natural
function prevents bleeding. If blood is drawn into a tube without
anticoagulant: plain red or SST, then the blood will clot naturally and
separate into liquid and cells. This liquid is called serum. It is the fluid
portion of a blood clot. It does not contain fibrinogen, therefore coagulation
tests cannot be performed because the coagulation factors (fibrinogen) have
been used in the process of clot formation.
3- Plasma - If anticoagulants are added to the tube: EDTA, Sodium citrate,
heparin, etc., the blood will not clot. Blood outside the body with
anticoagulant is referred to as whole blood. Whole blood can still be
separated into liquid and cells. This liquid is called plasma. It is the liquid
portion of blood when the tube contains anticoagulant. The use of an
anticoagulant preserves the fibrinogens in the plasma, so it may be used in a
coagulation test.
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Lab 1
Ali Abdulrasool Hussein
Biochemical tests in clinical medicine
 Lipid profile
 Diabetic profile
 Kidney profile
 Liver profile
 Bone profile
 Electrolyte profile
Laboratory work flow cycle:
The flow cycle includes the entire steps of laboratory test, starting from test
ordering by a doctor until reporting the results.
Three phases of laboratory testing:
 Pre-analytical: test ordering, sample collection, transport and processing
 Analytical-testing
 Post-analytical: results transmission, interpretation, follow-up, retesting
micropipette
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Lab 1
Ali Abdulrasool Hussein
SPECTROPHOTOMETER
Water bath
A(Test) − A(Blank)
𝐶(𝑇𝑒𝑠𝑡) =
∗ 𝐶(𝑆𝑡𝑎𝑛𝑑𝑒𝑟)
A(Stander) − A(Blank)
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