Clinical Biochemistry Test Directory
Explore routine and specialized biochemical investigations covering liver, kidney, diabetes, lipids, electrolytes, hormones, cardiac markers, proteins, vitamins and metabolic disorders. Understand what each test measures and how results are used in clinical practice.
What is clinical biochemistry?
Clinical biochemistry investigates chemical constituents of blood, urine and other body fluids to support diagnosis, disease monitoring, risk assessment and treatment decisions. Results must be interpreted alongside the patient's clinical history, specimen quality, reference intervals and relevant analytical limitations.Liver Function Test (LFT)
Evaluates liver-associated enzymes, bilirubin and proteins to support assessment of hepatocellular injury, cholestasis and synthetic function.
Clinical interpretation
Specimen: Serum or plasma as validated.
Clinical use: Assessment of liver injury patterns, jaundice and selected chronic liver disorders.
Interpretation: Interpret individual analytes and patterns rather than treating LFT as a single diagnostic test. Albumin and bilirubin have important non-hepatic influences.
ALT (Alanine Aminotransferase)
An enzyme measurement commonly used to assess hepatocellular injury.
Clinical interpretation
Specimen: Serum or validated plasma.
Clinical use: Investigation of suspected liver injury and monitoring of selected conditions.
Limitations: ALT magnitude does not independently establish the cause or severity of liver disease.
AST (Aspartate Aminotransferase)
Measures an enzyme found in liver, skeletal muscle, cardiac muscle and other tissues.
Clinical interpretation
Clinical use: Assessment of liver-associated enzyme abnormalities.
Interpretation: Consider ALT, CK, clinical context and possible haemolysis. AST is not liver-specific.
Gamma-Glutamyl Transferase (GGT)
Supports evaluation of hepatobiliary enzyme abnormalities and cholestatic patterns.
Clinical interpretation
Clinical use: Interpretation of elevated ALP and assessment of hepatobiliary abnormalities.
Limitations: GGT is nonspecific and may be influenced by medicines, alcohol and metabolic factors.
Total & Direct Bilirubin
Measures bilirubin to support the investigation of jaundice and bilirubin metabolism.
Clinical interpretation
Specimen: Protect from excessive light according to laboratory protocol.
Clinical use: Evaluation of jaundice, haemolysis and hepatobiliary disease.
Interpretation: Consider fractionation, liver enzymes, haemolysis markers and clinical context.
Kidney Function Test (KFT)
Assesses biochemical markers used in evaluating kidney function and electrolyte balance.
Clinical interpretation
Clinical use: Evaluation and monitoring of kidney disorders and selected metabolic disturbances.
Interpretation: Review creatinine trends, eGFR, urine albumin and electrolytes. The exact panel varies by laboratory.
Serum Creatinine
A commonly used marker for estimating glomerular filtration and monitoring kidney function.
Clinical interpretation
Clinical use: Kidney function assessment and calculation of estimated GFR.
Limitations: Influenced by muscle mass, diet, some medicines and non-steady-state kidney function.
Estimated GFR (eGFR)
Estimates glomerular filtration using serum creatinine and an appropriate validated equation.
Clinical interpretation
Clinical use: Classification and monitoring of kidney function.
Interpretation: Chronic kidney disease generally requires abnormalities persisting for at least three months or other qualifying evidence.
Limitations: Less reliable in acute kidney injury and some unusual body-composition states.
Urea / Blood Urea Nitrogen
Measures a nitrogen-containing waste product influenced by renal excretion and protein metabolism.
Clinical interpretation
Clinical use: Assessment alongside creatinine, hydration status and other findings.
Limitations: Influenced by protein intake, catabolism, gastrointestinal bleeding and hydration.
Urine Albumin-to-Creatinine Ratio
Quantifies urine albumin relative to creatinine to assess kidney damage, particularly in diabetes and hypertension.
Clinical interpretation
Specimen: Preferably a spot urine specimen as recommended by the laboratory.
Clinical use: Kidney-risk assessment and monitoring.
Interpretation: Confirm persistent abnormalities as clinically appropriate; transient elevation may occur with infection, exercise or acute illness.
Fasting Plasma Glucose
Measures blood glucose after an appropriate fasting period.
Clinical interpretation
Clinical use: Screening and diagnosis of diabetes and assessment of glycaemic status.
Note: Diagnostic thresholds and confirmation requirements should follow current guidelines and the patient's clinical circumstances.
Postprandial Blood Glucose
Measures glucose at a specified interval after a meal or as prescribed.
Clinical interpretation
Clinical use: Assessment of post-meal glycaemia and selected diabetes-monitoring protocols.
Note: Meal composition and collection timing influence results. PP glucose is not interchangeable with a standardized oral glucose tolerance test.
HbA1c (Glycated Haemoglobin)
Reflects average glycaemic exposure over approximately the preceding two to three months.
Clinical interpretation
Clinical use: Diabetes diagnosis in appropriate settings and long-term glycaemic monitoring.
Limitations: Haemoglobin variants, altered red-cell survival, recent blood loss or transfusion and some anaemias can affect interpretation.
Oral Glucose Tolerance Test (OGTT)
Measures glucose response following a standardized oral glucose load.
Clinical interpretation
Clinical use: Investigation of glucose intolerance and diagnosis of gestational diabetes under applicable protocols.
Note: Glucose dose, timing, preparation and diagnostic thresholds depend on the clinical indication and guideline used.
Serum Insulin
Measures circulating insulin in selected investigations of glucose regulation.
Clinical interpretation
Clinical use: Selected hypoglycaemia investigations and evaluation of insulin secretion.
Limitations: Interpretation depends on simultaneous glucose, timing, medicines and assay characteristics. Insulin alone does not diagnose insulin resistance.
Lipid Profile
Evaluates circulating lipids and lipoprotein-associated cholesterol for cardiovascular risk assessment.
Clinical interpretation
Clinical use: Cardiovascular risk assessment and monitoring of lipid-lowering therapy.
Interpretation: Consider overall cardiovascular risk, triglyceride concentration and whether LDL-C is measured or calculated.
Apolipoprotein B (ApoB)
Estimates the number of circulating atherogenic lipoprotein particles through their major structural apolipoprotein.
Clinical interpretation
Clinical use: Selected cardiovascular risk assessments, especially when lipid measures are discordant.
Note: Interpret with the lipid profile and clinical risk; treatment goals depend on the patient's risk category.
Lipoprotein(a) [Lp(a)]
Measures a largely genetically determined lipoprotein associated with atherosclerotic cardiovascular risk.
Clinical interpretation
Clinical use: Refinement of cardiovascular risk assessment in selected patients.
Note: Report units accurately. mg/dL and nmol/L are not reliably interchangeable using a universal conversion factor.
Serum Electrolytes
Measures key electrolytes involved in fluid balance, nerve function and acid-base regulation.
Clinical interpretation
Clinical use: Assessment of fluid disorders, kidney disease, acid-base abnormalities and medicine effects.
Limitations: Haemolysis can falsely increase potassium. Collection and transport conditions matter.
Total Calcium
Measures total circulating calcium, including protein-bound and free fractions.
Clinical interpretation
Clinical use: Investigation of parathyroid, bone, renal and selected malignancy-related disorders.
Interpretation: Albumin affects total calcium. Consider ionized calcium when clinically indicated; correction equations have limitations.
Ionized Calcium
Measures the physiologically active fraction of calcium.
Clinical interpretation
Clinical use: Selected critical-care, parathyroid and complex calcium disorders.
Limitations: pH changes and exposure to air can alter results. Follow validated collection and processing procedures.
Serum Magnesium
Assesses circulating magnesium in patients with electrolyte, neuromuscular or cardiac abnormalities.
Clinical interpretation
Clinical use: Evaluation of suspected magnesium imbalance and monitoring of replacement.
Note: Haemolysis can affect results. Serum concentration does not fully represent total-body magnesium stores.
Serum Phosphate
Measures inorganic phosphate important for bone mineralization and cellular energy metabolism.
Clinical interpretation
Clinical use: Evaluation of mineral disorders, kidney disease and selected metabolic conditions.
Interpretation: Consider calcium, magnesium, PTH, vitamin D and renal function where relevant.
Uric Acid
Measures circulating urate in the assessment of gout and selected metabolic or renal conditions.
Clinical interpretation
Clinical use: Evaluation and monitoring of hyperuricaemia in appropriate contexts.
Note: Serum urate alone neither confirms nor excludes an acute gout attack.
High-Sensitivity Troponin I / T
Detects myocardial injury and supports assessment of suspected acute coronary syndromes.
Clinical interpretation
Clinical use: Acute chest-pain pathways and evaluation of myocardial injury.
Interpretation: Use assay-specific decision limits and serial change with ECG and clinical findings. Elevated troponin is not specific to myocardial infarction.
BNP / NT-proBNP
Measures natriuretic peptides that support evaluation of suspected heart failure.
Clinical interpretation
Clinical use: Assessment of dyspnoea and selected heart-failure evaluations.
Limitations: Age, renal function, obesity and other cardiac conditions influence concentrations. BNP and NT-proBNP values are not interchangeable.
CK-MB
Measures the MB fraction of creatine kinase, historically used in cardiac injury assessment.
Clinical interpretation
Clinical use: Selected circumstances where clinically justified.
Note: High-sensitivity cardiac troponin is generally preferred for evaluating myocardial injury.
Total Protein, Albumin & Globulin
Measures major serum proteins and supports evaluation of nutritional, hepatic, renal and immune-related disorders.
Clinical interpretation
Clinical use: Investigation of abnormal protein concentrations and fluid balance.
Interpretation: Consider liver function, urinary protein loss, inflammation, immunoglobulins and serum protein electrophoresis when indicated.
C-Reactive Protein (CRP)
Measures an acute-phase protein that rises in many inflammatory conditions.
Clinical interpretation
Clinical use: Assessment and monitoring of inflammation and selected infections.
Limitations: CRP is nonspecific and cannot independently identify the cause of inflammation.
Procalcitonin (PCT)
Measures a biomarker used alongside clinical assessment in selected suspected bacterial infections.
Clinical interpretation
Clinical use: Selected infection and antimicrobial-stewardship pathways.
Note: PCT must not be used alone to diagnose or exclude sepsis or to delay urgent treatment.
Serum Protein Electrophoresis (SPEP)
Separates serum proteins into fractions and helps characterize abnormal protein patterns.
Clinical interpretation
Clinical use: Investigation of monoclonal gammopathy and selected protein abnormalities.
Note: Immunofixation and serum free light chains may be needed when a plasma-cell disorder is suspected.
Quantitative Immunoglobulins
Measures IgG, IgA and IgM to support evaluation of immune and protein abnormalities.
Clinical interpretation
Clinical use: Selected immune-deficiency, inflammatory and plasma-cell disorder evaluations.
Note: Quantitative immunoglobulins do not independently establish antibody function or clonality.
25-OH Vitamin D
The main circulating marker used to assess vitamin D status.
Clinical interpretation
Clinical use: Evaluation of suspected deficiency and selected bone or mineral disorders.
Note: Interpret with clinical context and relevant calcium, phosphate, PTH and renal findings.
Vitamin B12
Measures circulating cobalamin in the evaluation of suspected vitamin B12 deficiency.
Clinical interpretation
Clinical use: Investigation of selected anaemias, neurological symptoms and nutritional concerns.
Note: Borderline or discordant results may require clinical assessment and additional markers such as methylmalonic acid where appropriate.
Folate (Vitamin B9)
Assesses folate status in selected nutritional and haematological investigations.
Clinical interpretation
Clinical use: Investigation of suspected folate deficiency and macrocytic anaemia.
Note: Interpret alongside vitamin B12 and the blood count.
Homocysteine
Measures a sulfur-containing amino acid associated with several metabolic pathways.
Clinical interpretation
Clinical use: Selected investigations of B-vitamin status and inherited metabolic disorders.
Limitations: Influenced by renal function, folate, B12, B6 and other factors. It is not a standalone cardiovascular screening test.
Thyroid-Stimulating Hormone (TSH)
Common first-line biochemical test for evaluating thyroid function in many clinical settings.
Clinical interpretation
Clinical use: Investigation and monitoring of thyroid disorders.
Interpretation: Consider free T4, pregnancy status, medicines, acute illness and timing when results are unexpected.
Free T4 (FT4)
Measures the unbound fraction of thyroxine circulating in blood.
Clinical interpretation
Clinical use: Classification of thyroid dysfunction alongside TSH and clinical findings.
Limitations: Some medicines, binding-protein changes and assay interference can affect results.
Serum Cortisol
Measures cortisol to support selected investigations of adrenal function.
Clinical interpretation
Clinical use: Selected evaluations of suspected adrenal insufficiency or cortisol excess.
Note: Collection time, medicines, stress, binding proteins and the clinical question determine interpretation. Dynamic testing may be required.
Prolactin
Measures a pituitary hormone involved in lactation and reproductive regulation.
Clinical interpretation
Clinical use: Evaluation of selected menstrual, fertility and pituitary disorders.
Note: Stress, medicines, pregnancy and macroprolactin can affect interpretation.
Total Testosterone
Measures circulating total testosterone for selected endocrine and reproductive investigations.
Clinical interpretation
Clinical use: Evaluation of suspected androgen excess or deficiency.
Note: Timing, age, sex, SHBG, medicines and clinical context matter. Low results may require repeat morning testing according to applicable guidance.
Serum Iron
Measures circulating iron bound mainly to transferrin.
Clinical interpretation
Clinical use: Investigation of suspected iron disorders as part of an iron profile.
Note: Serum iron varies with time and recent intake; it should not be interpreted in isolation.
Ferritin
Reflects iron stores in many clinical settings and is also an acute-phase reactant.
Clinical interpretation
Clinical use: Investigation of suspected iron deficiency and iron overload.
Limitations: Inflammation, liver disease and other conditions may elevate ferritin despite restricted iron availability.
TIBC & Transferrin Saturation
Assesses iron-binding capacity and the proportion of transferrin carrying iron.
Clinical interpretation
Clinical use: Differentiation of selected iron deficiency, inflammation and iron overload patterns.
Note: Interpret with ferritin, CBC and inflammatory status.
Serum Amylase
Measures an enzyme produced by the pancreas and other tissues.
Clinical interpretation
Clinical use: Selected investigations of suspected pancreatitis and other causes of enzyme elevation.
Note: Lipase is generally preferred for diagnosing acute pancreatitis when available and appropriate.
Serum Lipase
Measures a pancreatic digestive enzyme used in the evaluation of suspected pancreatitis.
Clinical interpretation
Clinical use: Investigation of acute pancreatic injury.
Interpretation: Combine the result with characteristic symptoms and imaging when needed; lipase elevation can occur in other conditions.
Serum Immunofixation Electrophoresis (IFE)
Characterizes immunoglobulin heavy and light chains to help identify monoclonal proteins.
Clinical interpretation
Clinical use: Characterization of suspected monoclonal gammopathy and selected protein abnormalities.
Note: Interpret alongside SPEP, serum free light chains and the clinical picture as appropriate.
Serum Free Light Chains
Measures free kappa and lambda light chains and their ratio.
Clinical interpretation
Clinical use: Investigation and monitoring of selected plasma-cell disorders.
Limitations: Kidney function influences concentrations and ratios; interpret with the appropriate assay-specific reference interval.
Plasma Ammonia
Measures ammonia in selected investigations of metabolic or hepatic disorders.
Clinical interpretation
Specimen: Follow the performing laboratory's validated collection, transport and processing requirements.
Clinical use: Selected metabolic investigations and evaluation of suspected hyperammonaemia.
Limitations: Pre-analytical error can cause falsely elevated results. Ammonia alone does not diagnose hepatic encephalopathy.
Lactate
Measures lactate to support evaluation of altered tissue perfusion and selected metabolic disturbances.
Clinical interpretation
Clinical use: Selected critical-care, shock and metabolic evaluations.
Limitations: Collection technique, tourniquet use, exertion, medicines and processing delays may affect results. Interpret within the clinical context.
Intact Parathyroid Hormone (PTH)
Measures circulating PTH to help investigate calcium and phosphate disorders.
Clinical interpretation
Clinical use: Evaluation of selected parathyroid and mineral disorders.
Interpretation: Review calcium, phosphate, vitamin D and renal function. Follow the assay's specimen handling requirements.
Creatine Kinase (CK)
Measures an enzyme associated particularly with skeletal muscle and other tissues.
Clinical interpretation
Clinical use: Investigation of suspected muscle injury and selected neuromuscular disorders.
Limitations: Exercise, trauma, injections and medicines may affect CK concentrations.
Lactate Dehydrogenase (LDH)
Measures a widely distributed intracellular enzyme that may increase with tissue injury or haemolysis.
Clinical interpretation
Clinical use: Selected evaluations of haemolysis, tissue injury and disease monitoring.
Limitations: LDH is nonspecific and particularly susceptible to interference from haemolysis of the specimen.
Understanding biochemistry reports
Reference intervals
Use the performing laboratory's method-specific intervals and appropriate age or population considerations.
Analytical interference
Haemolysis, lipaemia, icterus, medicines and specimen handling can affect selected assays.
Clinical correlation
Interpret abnormal findings with symptoms, medical history, trends and complementary tests.
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