07/30/2025
Introduction to
Clinical Biochemistry
Muhammad Muneeb
(Lecturer – RIPS)
Purpose of Clinical Chemistry Tests
• Measure levels of substances found normally in
human blood that have biological functions
Examples: Glucose, Calcium
• Detect or measure non-functional metabolites or
waste products
Examples: Creatinine, Blood Urea Nitrogen (BUN)
• Detect or measure substances that indicate cell
damage or disease.
Examples: Liver enzymes, such as ALT, Cardiac
enzymes, such as CK-MB (Creatine Kinase-Myocardial B-
Fraction)
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Types of Specimen
• Whole blood, serum or plasma.
• The most common specimen is serum, collected in a
tube with no anticoagulant so that the blood can clot
• Urine – often 24 hour collections
• Others – Cerebrospinal Spinal Fluid (CSF) and other
fluids
Collection & Handling of Blood Specimen
• Blood collection tubes for obtaining serum - Serum
Separator Tubes (SST) do not have an anticoagulant
but do contain a gel substance which will form an
interface between the clot and the serum when the
blood specimen is centrifuged. These tubes are
sometimes referred to as “Tiger Tops”.
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Collection & Handling of Blood Specimen
• Some compounds of specimens are increased or
decreased after eating (ex. Glucose, triglycerides),
so it is important to know what the test and collection
method call for. Specimens for these tests are usually
collected in a fasting state.
• Sometimes serum or plasma appears lipemia (milky)
after a patient has eaten a fatty meal
• Lipemia affects most chemistry analyses.
• The blood must be recollected when the patient is
fasting
Clinical Chemistry Tests
• Normal or Reference Values – range of values for a
particular chemistry test from healthy individuals
• Chemistry Panel grouping – some tests are
“bundled” according to the system or organ targeted.
Examples: thyroid panel, liver panel, cardiac panel,
kidney panel, basic metabolic panel, etc.
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Protein Panel
• Proteins – essential components of cells and body
fluids. Some made by body, others acquired from diet
• Provides information about state of hydration,
nutrition and liver function, since most of the
serum proteins are made in the liver
Electrolytes
• Includes sodium (Na), potassium (K), chloride (Cl) and
bicarbonate (HCO3-)
• Collectively these have a great effect on hydration,
acid-base balance and osmotic pressure as well as
pH and heart and muscle contraction
• Levels differ depending on if inside vs. outside cells
• Important in transport of substances into and out of
cells
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Minerals
1. Calcium:
• Used in coagulation and muscle contraction
• 99% is in skeleton and is not metabolically active
• Influenced by vitamin D, parathyroid hormone,
estrogen and calcitonin
• Hypercalcemia – occurs in hyperparathyroidism,
bone malignancies, hormone disorders, excessive
vitamin D, and acidosis; may cause kidney stones
• Hypocalcaemia – can cause tetany; occurs in
hyperparathyroidism, vitamin D deficiency, poor
dietary absorption and kidney disease
Minerals
2. Phosphorus:
• 80% in bone and rest in energy compounds such as
ATP
• Influenced by calcium and certain hormones
3. Iron:
• Essential for hemoglobin
• Deficiency results in anemia; may be caused by lack of
iron in diet, poor absorption, poor release of stored iron
or loss due to bleeding
• Increased in hemolytic anemia, increased iron intake
or blocked synthesis of iron-containing compounds,
such as in lead poisoning
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Kidney Function Tests
1. Serum Creatinine:
• Best test for overall kidney function; not affected by
diet or hormone levels
• Waste product of muscle metabolism. Serum
creatinine rises when kidney function is impaired
2. Uric Acid:
• Formed from breakdown of nucleic acids and excreted
as a waste product by kidneys
• Increased in kidney disease, but most often used to
diagnosis gout (pain in joints, mainly big toe, due to
precipitated uric acid crystals). It is also increased in
increased cell destruction, such as after massive
radiation or chemotherapy
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Kidney Function Tests
3. BUN (Blood Urea Nitrogen):
• BUN is surplus amino acids that are converted to urea
and excreted by kidneys as a waste product.
• BUN influenced by diet and hormones, so it is NOT as
good an indicator of renal function as serum creatinine
levels
• BUN increased in kidney disease, high protein diet,
and after administration of steroids
• BUN decreased in starvation, pregnancy and in
persons on a low protein diet
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Liver Function Tests
1. Liver Functions:
• Synthesizes glycogen from glucose
• Makes plasma proteins (albumin, lipoproteins,
coagulation proteins)
• Forms cholesterol and degrades it into bile acids,
which emulsifies fats for absorption
• Stores iron, glycogen, vitamins and other substances
• Destroys old blood cells and recycles components of
hemoglobin
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Liver Function Tests
2. Liver Enzymes:
• Levels increase following damage to liver tissues:
• Alkaline Phosphatase (ALP or AP) - Greatly
increased in liver tumors and lesions; moderately
increased in diseases such as hepatitis
• Alanine Aminotransferase (ALT; formerly called
SGPT) - Increases up to 10x in cirrhosis, infections or
tumors and up to 100x in viral or toxic hepatitis
• Asparate Aminotransferase (AST; formerly called
SGOT) - Increased in liver disease, but also in heart
attacks
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Liver Function Tests
2. Liver Enzymes:
• Gamma Glutamyl Transferase (GGT) - Often used
to monitor patients recovering from hepatitis and
cirrhosis
• Lactate Dehydrogenase (LD) - Increased in liver
disease and following heart attacks
3. Total Bilirubin:
• Waste product of hemoglobin breakdown
• Increased in excessive RBC breakdown, such as
hemolytic anemia, or impaired liver function or some
sort of obstruction, such as a tumor or gall stone
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Lipid Metabolism Tests
1. Cholesterol:
• Present in all tissues
• Serves as the skeleton for many hormones
• Recommended to be less than 200 mg/dL in adults)
• LDL = “bad” cholesterol; HDL = “good” cholesterol
• 2. Triglycerides:
• Main storage form of lipids, comprising 95% of fat
tissue
• Hyperlipidemia – having high blood levels of
triglycerides – may increase risk of heart attack
• 3. Carbohydrate Metabolism Tests:
• Glucose - Largely regulated by insulin
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Thyroid Function Tests
• Thyroid Stimulating Hormone (TSH) - Inverse
relationship to thyroid function (the higher the TSH,
the lower the thyroid function and vice versa)
• Other less common thyroid tests include T3
(Triiodothyronine) and T4 (thyroxine)
• Hypothyroidism – underactive thyroid gland
• Hyperthyroidism – overactive thyroid gland
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Normal Values for Some Tests
LFTs:
• ALT. 7 to 55 units per liter (U/L)
• AST. 8 to 48 U/L
• ALP. 45 to 115 U/L
• Albumin. 3.5 to 5.0 grams per deciliter (g/dL)
• Total protein. 6.3 to 7.9 g/dL
• Bilirubin. 0.1 to 1.0 mg/dL
• GGT. 9 to 48 U/L
• LD. 122 to 222 U/L
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Normal Values for Some Tests
Lipid Panel
Desirable Borderline High Risk
Cholesterol 200-239 mg/dl 240 mg/dl
Triglycerides 150-199 mg/dl 200-499 mg/dl
HDL Cholesterol 60 mg/dl 35-45 mg/dl
LDL Cholesterol 60-130 mg/dl 130-159 mg/dl 160-189 mg/dl
Cholesterol/HDL 4.0 5.0 6.0
ratio
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Normal Values for Some Tests
Troponin
• TnI: Less than 0.35 (mcg/L)
• TnT: Less than 0.2 (mcg/L)
• CK-MB (creatine kinase-myocardial band) normal
values:0–3 (mcg/L)
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Normal Values for Some Tests
Test Abbreviation Typical Ranges
Serum thyroxine T4 4.6-12 ug/dl
Free thyroxine fraction FT4F 0.03-0.005%
Free Thyroxine FT4 0.7-1.9 ng/dl
Thyroid hormone binding THBR 0.9-1.1
ratio
Free Thyroxine index FT4I 4-11
Serum Triiodothyronine T3 80-180 ng/dl
Free Triiodothyronine l FT3 230-619 pg/d
Free T3 Index FT3I 80-180
Radioactive iodine uptake RAIU 10-30%
Serum thyrotropin TSH 0.5-6 uU/ml
Thyroxine-binding globulin TBG 12-20 ug/dl T4 +1.8
ugm
TRH stimulation test Peak TSH 9-30 uIU/ml at 20-30
min
Serum thyroglobulin l Tg 0-30 ng/m
Thyroid microsomal TMAb Varies with method
antibody titer
Thyroglobulin antibody titer TgAb Varies with method
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Assignment 1
Blood Glucose and Diagnosis of Diabetes
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Assignment 2
Diagnosis of Lipid Metabolism Disorders
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Assignment 3
Water and Electrolyte Balances
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Assignment 4
Diagnosis of Protein Metabolism Disorders
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Assignment 5
Diagnosis of Enzyme Metabolism Disorders
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Assignment 6
Diagnosis of Hormonal Metabolism Disorders
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Thank you
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