Common tests in Clinical Biochemistry
- Total protein (TP) – Biuret method – in the presence of peptides, the Copper (II) ion forms
mauve-coloured coordination complexes in an alkaline solution
- Albumin (Alb) – Bromocresol green – dye-binding assay, colour intensity is indicative of
albumin concentration
- Urea/ Helicobacter pylori – Urease – used for diagnosis of pathogens such as H. pylori,
which are capable of releasing the enzyme Urease, catalysing the breakdown of urea to
ammonia and CO2
- Uric acid (UA) – Uricase – monitor levels of uric acid in the blood. Uricase acts on uric acid
to produce allantoin, CO2 and hydrogen peroxide
- Creatine (CRE) – Kinetic alkaline picrate – in an alkaline medium, picric acid reacts with
creatine to form an orange-coloured complex with alkaline picrate. Colour intensity is
directly proportional to creatine concentration
- Total bilirubin (TBil) – Diazonium salt – monitoring of bilirubin levels in the blood. Diazonium
salts react directly with bilirubin to form two coloured azobilirubin molecules
- Glucose (Glu) – Hexokinase/ G-6-PDH – the enzyme hexokinase catalyses the reaction
between glucose and ATP to form glucose-6-phosphate and ADP
- Total cholesterol – Cholesterol oxidase – cholesterol oxidases catalyse the oxidation and
isomerization of cholesterol to cholesten-3-one and hydrogen peroxide
- Triglycerides (TG) – Glycerol phosphate oxidase – determining serum triglyceride
concentration using the enzyme glycerol phosphate oxidase
- High density lipoprotein-cholesterol (HDL-C) – accelerator selective detergent – this test for
HDL-C works on the selective solubilising effect of detergent on differing lipoproteins
- Low density lipoprotein-cholesterol (LDL-C) – measured, liquid selective detergent –
ultracentrifugation and selective precipitation of LDL in serum
- Sodium (Na) – ion-selective electrode diluted (indirect) – ion-selective electrode testing
selectively for sodium ions (Na+)
- Potassium (K) - ion-selective electrode diluted (indirect) – ion-selective electrode testing
selectively for potassium ions (K+)
- Chloride (Cl) - ion-selective electrode diluted (indirect) – ion-selective electrode testing
selectively for Chloride ions (Cl-)
- Calcium (Ca) – Arsenazo-III dye – using a colorimetric approach, protein bound calcium
ions are released by acidification, causing the Ca + ions to form a complex with Arsenazo-III
dye under alkaline conditions
- Inorganic phosphorus (IP) – Phosphomolybdate – acidification of sample and ammonium
molybdate is added. In the presence of inorganic phosphorus, a bright yellow precipitate of
phosphomolybdate will form
- Total protein (TP) – Biuret method – in the presence of peptides, the Copper (II) ion forms
mauve-coloured coordination complexes in an alkaline solution
- Albumin (Alb) – Bromocresol green – dye-binding assay, colour intensity is indicative of
albumin concentration
- Urea/ Helicobacter pylori – Urease – used for diagnosis of pathogens such as H. pylori,
which are capable of releasing the enzyme Urease, catalysing the breakdown of urea to
ammonia and CO2
- Uric acid (UA) – Uricase – monitor levels of uric acid in the blood. Uricase acts on uric acid
to produce allantoin, CO2 and hydrogen peroxide
- Creatine (CRE) – Kinetic alkaline picrate – in an alkaline medium, picric acid reacts with
creatine to form an orange-coloured complex with alkaline picrate. Colour intensity is
directly proportional to creatine concentration
- Total bilirubin (TBil) – Diazonium salt – monitoring of bilirubin levels in the blood. Diazonium
salts react directly with bilirubin to form two coloured azobilirubin molecules
- Glucose (Glu) – Hexokinase/ G-6-PDH – the enzyme hexokinase catalyses the reaction
between glucose and ATP to form glucose-6-phosphate and ADP
- Total cholesterol – Cholesterol oxidase – cholesterol oxidases catalyse the oxidation and
isomerization of cholesterol to cholesten-3-one and hydrogen peroxide
- Triglycerides (TG) – Glycerol phosphate oxidase – determining serum triglyceride
concentration using the enzyme glycerol phosphate oxidase
- High density lipoprotein-cholesterol (HDL-C) – accelerator selective detergent – this test for
HDL-C works on the selective solubilising effect of detergent on differing lipoproteins
- Low density lipoprotein-cholesterol (LDL-C) – measured, liquid selective detergent –
ultracentrifugation and selective precipitation of LDL in serum
- Sodium (Na) – ion-selective electrode diluted (indirect) – ion-selective electrode testing
selectively for sodium ions (Na+)
- Potassium (K) - ion-selective electrode diluted (indirect) – ion-selective electrode testing
selectively for potassium ions (K+)
- Chloride (Cl) - ion-selective electrode diluted (indirect) – ion-selective electrode testing
selectively for Chloride ions (Cl-)
- Calcium (Ca) – Arsenazo-III dye – using a colorimetric approach, protein bound calcium
ions are released by acidification, causing the Ca + ions to form a complex with Arsenazo-III
dye under alkaline conditions
- Inorganic phosphorus (IP) – Phosphomolybdate – acidification of sample and ammonium
molybdate is added. In the presence of inorganic phosphorus, a bright yellow precipitate of
phosphomolybdate will form
