Clinical chemistry (also known as chemical pathology, clinical biochemistry or medical biochemistry) is the area of

chemistry Chemistry is the scientific study of the properties and behavior of matter. It is a natural science that covers the elements that make up matter to the compounds made of atoms, molecules and ions: their composition, structure, proper ...

that is generally concerned with analysis of

bodily fluids Body fluids, bodily fluids, or biofluids, sometimes body liquids, are liquids within the human body. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52-55%). ...

for

diagnostic Diagnosis is the identification of the nature and cause of a certain phenomenon. Diagnosis is used in many different disciplines, with variations in the use of logic, analytics, and experience, to determine "cause and effect". In systems enginee ...

and therapeutic purposes. It is an applied form of

biochemistry Biochemistry or biological chemistry is the study of chemical processes within and relating to living organisms. A sub-discipline of both chemistry and biology, biochemistry may be divided into three fields: structural biology, enzymology and ...

(not to be confused with medicinal chemistry, which involves basic research for

drug development Drug development is the process of bringing a new pharmaceutical drug to the market once a lead compound has been identified through the process of drug discovery. It includes preclinical research on microorganisms and animals, filing for re ...

). The discipline originated in the late 19th century with the use of simple

chemical reaction A chemical reaction is a process that leads to the chemical transformation of one set of chemical substances to another. Classically, chemical reactions encompass changes that only involve the positions of electrons in the forming and breaking ...

tests for various components of

blood Blood is a body fluid in the circulatory system of humans and other vertebrates that delivers necessary substances such as nutrients and oxygen to the cells, and transports metabolic waste products away from those same cells. Blood in the cir ...

and

urine Urine is a liquid by-product of metabolism in humans and in many other animals. Urine flows from the kidneys through the ureters to the urinary bladder. Urination results in urine being excreted from the body through the urethra. Cellul ...

. In the many decades since, other techniques have been applied as science and technology have advanced, including the use and measurement of

enzyme Enzymes () are proteins that act as biological catalysts by accelerating chemical reactions. The molecules upon which enzymes may act are called substrates, and the enzyme converts the substrates into different molecules known as products ...

activities,

spectrophotometry Spectrophotometry is a branch of electromagnetic spectroscopy concerned with the quantitative measurement of the reflection or transmission properties of a material as a function of wavelength. Spectrophotometry uses photometers, known as sp ...

electrophoresis Electrophoresis, from Ancient Greek ἤλεκτρον (ḗlektron, "amber") and φόρησις (phórēsis, "the act of bearing"), is the motion of dispersed particles relative to a fluid under the influence of a spatially uniform electric fi ...

, and

immunoassay An immunoassay (IA) is a biochemical test that measures the presence or concentration of a macromolecule or a small molecule in a solution through the use of an antibody (usually) or an antigen (sometimes). The molecule detected by the immunoa ...

. There are now many

blood test A blood test is a laboratory analysis performed on a blood sample that is usually extracted from a vein in the arm using a hypodermic needle, or via fingerprick. Multiple tests for specific blood components, such as a glucose test or a choles ...

s and clinical urine tests with extensive diagnostic capabilities. Most current laboratories are now highly automated to accommodate the high workload typical of a hospital laboratory. Tests performed are closely monitored and quality controlled. All biochemical tests come under chemical pathology. These are performed on any kind of

body fluid Body fluids, bodily fluids, or biofluids, sometimes body liquids, are liquids within the human body. In lean healthy adult men, the total body water is about 60% (60–67%) of the total body weight; it is usually slightly lower in women (52-55%). ...

, but mostly on serum or plasma. Serum is the yellow watery part of blood that is left after blood has been allowed to clot and all blood cells have been removed. This is most easily done by centrifugation, which packs the denser blood cells and platelets to the bottom of the centrifuge tube, leaving the liquid serum fraction resting above the packed cells. This initial step before analysis has recently been included in instruments that operate on the " integrated system" principle. Plasma is in essence the same as serum, but is obtained by centrifuging the blood ''without'' clotting. Plasma is obtained by centrifugation ''before'' clotting occurs. The type of test required dictates what type of sample is used. A large

medical laboratory A medical laboratory or clinical laboratory is a laboratory where tests are conducted out on clinical specimens to obtain information about the health of a patient to aid in diagnosis, treatment, and prevention of disease. Clinical Medical labor ...

will accept samples for up to about 700 different kinds of tests. Even the largest of laboratories rarely do all these tests themselves, and some must be referred to other labs. This large array of tests can be categorised into sub-specialities of: *General or routine chemistry – commonly ordered blood chemistries (e.g., liver and kidney function tests). *Special chemistry - elaborate techniques such as

, and manual testing methods. * Clinical endocrinology – the study of

hormone A hormone (from the Greek participle , "setting in motion") is a class of signaling molecules in multicellular organisms that are sent to distant organs by complex biological processes to regulate physiology and behavior. Hormones are required ...

s, and diagnosis of endocrine disorders. *

Toxicology Toxicology is a scientific discipline, overlapping with biology, chemistry, pharmacology, and medicine, that involves the study of the adverse effects of chemical substances on living organisms and the practice of diagnosing and treating e ...

– the study of drugs of abuse and other chemicals. * Therapeutic Drug Monitoring – measurement of therapeutic medication levels to optimize dosage. *

Urinalysis Urinalysis, a portmanteau of the words ''urine'' and ''analysis'', is a panel of medical tests that includes physical (macroscopic) examination of the urine, chemical evaluation using urine test strips, and microscopic examination. Macroscopic e ...

– chemical analysis of urine for a wide array of diseases, along with other fluids such as CSF and

effusion In physics and chemistry, effusion is the process in which a gas escapes from a container through a hole of diameter considerably smaller than the mean free path of the molecules. Such a hole is often described as a ''pinhole'' and the escap ...

s *Fecal analysis – mostly for detection of gastrointestinal disorders.

Tests

Common clinical chemistry tests include: ;Electrolytes *

Sodium Sodium is a chemical element with the symbol Na (from Latin ''natrium'') and atomic number 11. It is a soft, silvery-white, highly reactive metal. Sodium is an alkali metal, being in group 1 of the periodic table. Its only stable ...

Potassium Potassium is the chemical element with the symbol K (from Neo-Latin '' kalium'') and atomic number19. Potassium is a silvery-white metal that is soft enough to be cut with a knife with little force. Potassium metal reacts rapidly with atmos ...

Chloride The chloride ion is the anion (negatively charged ion) Cl−. It is formed when the element chlorine (a halogen) gains an electron or when a compound such as hydrogen chloride is dissolved in water or other polar solvents. Chloride s ...

Bicarbonate In inorganic chemistry, bicarbonate (IUPAC-recommended nomenclature: hydrogencarbonate) is an intermediate form in the deprotonation of carbonic acid. It is a polyatomic anion with the chemical formula . Bicarbonate serves a crucial biochemi ...

;Renal (kidney) function tests * Creatinine *

Blood urea nitrogen Blood urea nitrogen (BUN) is a medical test that measures the amount of urea nitrogen found in blood. The liver produces urea in the urea cycle as a waste product of the digestion of protein. Normal human adult blood should contain 6 to 20 mg/dL ...

;Liver function tests * Total protein (serum) **

Albumin Albumin is a family of globular proteins, the most common of which are the serum albumins. All the proteins of the albumin family are water- soluble, moderately soluble in concentrated salt solutions, and experience heat denaturation. Album ...

** Globulins **A/G ratio (albumin-globulin) **

Protein electrophoresis Protein electrophoresis is a method for analysing the proteins in a fluid or an extract. The electrophoresis may be performed with a small volume of sample in a number of alternative ways with or without a supporting medium: SDS polyacrylamide gel ...

Urine protein Proteinuria is the presence of excess proteins in the urine. In healthy persons, urine contains very little protein; an excess is suggestive of illness. Excess protein in the urine often causes the urine to become foamy (although this symptom m ...

Bilirubin Bilirubin (BR) ( Latin for "red bile") is a red-orange compound that occurs in the normal catabolic pathway that breaks down heme in vertebrates. This catabolism is a necessary process in the body's clearance of waste products that arise from t ...

; direct; indirect; total *

Aspartate transaminase Aspartate transaminase (AST) or aspartate aminotransferase, also known as AspAT/ASAT/AAT or (serum) glutamic oxaloacetic transaminase (GOT, SGOT), is a pyridoxal phosphate (PLP)-dependent transaminase enzyme () that was first described by Arthur ...

(AST) *

Alanine transaminase Alanine transaminase (ALT) is a transaminase enzyme (). It is also called alanine aminotransferase (ALT or ALAT) and was formerly called serum glutamate-pyruvate transaminase or serum glutamic-pyruvic transaminase (SGPT) and was first characte ...

(ALT) * Gamma-glutamyl transpeptidase (GGT) *

Alkaline phosphatase The enzyme alkaline phosphatase (EC 3.1.3.1, alkaline phosphomonoesterase; phosphomonoesterase; glycerophosphatase; alkaline phosphohydrolase; alkaline phenyl phosphatase; orthophosphoric-monoester phosphohydrolase (alkaline optimum), systematic ...

(ALP) ;Cardiac markers *

H-FABP Heart-type fatty acid binding protein (hFABP) also known as mammary-derived growth inhibitor is a protein that in humans is encoded by the ''FABP3'' gene. Function Heart-type Fatty Acid-Binding Protein (H-FABP) is a small cytoplasmic protein ( ...

Troponin image:Troponin Ribbon Diagram.png, 400px, Ribbon representation of the human cardiac troponin core complex (52 kDa core) in the calcium-saturated form. Blue = troponin C; green = troponin I; magenta = troponin T.; ; rendered with PyMOL Troponin, ...

Myoglobin Myoglobin (symbol Mb or MB) is an iron- and oxygen-binding protein found in the cardiac and skeletal muscle tissue of vertebrates in general and in almost all mammals. Myoglobin is distantly related to hemoglobin. Compared to hemoglobin, myoglob ...

CK-MB The CPK-MB test (creatine phosphokinase-MB), also known as CK-MB test, is a cardiac marker used to assist diagnoses of an acute myocardial infarction, myocardial ischemia, or myocarditis. It measures the blood level of CK-MB (creatine kinase myoca ...

* B-type natriuretic peptide (BNP) ;Minerals *

Calcium Calcium is a chemical element with the symbol Ca and atomic number 20. As an alkaline earth metal, calcium is a reactive metal that forms a dark oxide-nitride layer when exposed to air. Its physical and chemical properties are most similar ...

Magnesium Magnesium is a chemical element with the symbol Mg and atomic number 12. It is a shiny gray metal having a low density, low melting point and high chemical reactivity. Like the other alkaline earth metals (group 2 of the periodic ...

Phosphate In chemistry, a phosphate is an anion, salt, functional group or ester derived from a phosphoric acid. It most commonly means orthophosphate, a derivative of orthophosphoric acid . The phosphate or orthophosphate ion is derived from phosph ...

;Blood disorders *

Iron Iron () is a chemical element with symbol Fe (from la, ferrum) and atomic number 26. It is a metal that belongs to the first transition series and group 8 of the periodic table. It is, by mass, the most common element on Earth, right in ...

Transferrin Transferrins are glycoproteins found in vertebrates which bind to and consequently mediate the transport of iron (Fe) through blood plasma. They are produced in the liver and contain binding sites for two Fe3+ ions. Human transferrin is encod ...

TIBC Total iron-binding capacity (TIBC) or sometimes transferrin iron-binding capacity is a medical laboratory test that measures the blood's capacity to bind iron with transferrin. Transferrin can bind two atoms of ferric iron (Fe3+) with high affinity ...

Vitamin B12 Vitamin B12, also known as cobalamin, is a water-soluble vitamin involved in metabolism. It is one of eight B vitamins. It is required by animals, which use it as a cofactor in DNA synthesis, in both fatty acid and amino acid metabolism. ...

Vitamin D Vitamin D is a group of Lipophilicity, fat-soluble secosteroids responsible for increasing intestinal absorption of calcium, magnesium, and phosphate, and many other biological effects. In humans, the most important compounds in this group ar ...

Folic acid Folate, also known as vitamin B9 and folacin, is one of the B vitamins. Manufactured folic acid, which is converted into folate by the body, is used as a dietary supplement and in food fortification as it is more stable during processing a ...

;Miscellaneous *

Glucose Glucose is a simple sugar with the molecular formula . Glucose is overall the most abundant monosaccharide, a subcategory of carbohydrates. Glucose is mainly made by plants and most algae during photosynthesis from water and carbon dioxide, u ...

C-reactive protein C-reactive protein (CRP) is an annular (ring-shaped) pentameric protein found in blood plasma, whose circulating concentrations rise in response to inflammation. It is an acute-phase protein of hepatic origin that increases following interleukin- ...

Glycated hemoglobin Glycated hemoglobin, also known as HbA1c, glycohemoglobin, hemoglobin A1c, A1C, is a form of hemoglobin (Hb) that is chemically linked to a sugar. Most monosaccharides, including glucose, galactose and fructose, spontaneously (i.e. non-enzymat ...

(HbA1c) * Uric acid * Arterial blood gases ( ⁺ P_CO₂, P_O₂) * Adrenocorticotropic hormone (ACTH) * Toxicological screening and

forensic toxicology Forensic toxicology is the use of toxicology and disciplines such as analytical chemistry, pharmacology and clinical chemistry to aid medical or legal investigation of death, poisoning, and drug use. The primary concern for forensic toxicology is ...

(

drug A drug is any chemical substance that causes a change in an organism's physiology or psychology when consumed. Drugs are typically distinguished from food and substances that provide nutritional support. Consumption of drugs can be via inhala ...

s and

toxin A toxin is a naturally occurring organic poison produced by metabolic activities of living cells or organisms. Toxins occur especially as a protein or conjugated protein. The term toxin was first used by organic chemist Ludwig Brieger (1849 ...

s) * Neuron-specific enolase (NSE) * fecal occult blood test (FOBT)

Panel tests

A set of commonly ordered tests are combined into a panel: * Basic metabolic panel (BMP) - 8 tests - sodium, potassium, chloride, bicarbonate, blood urea nitrogen (BUN), creatinine, glucose, calcium *

Comprehensive metabolic panel The comprehensive metabolic panel, or chemical screen (CMP; CPT code 80053), is a panel of 14 blood tests that serves as an initial broad medical screening tool. The CMP provides a rough check of kidney function, liver function, diabetic and par ...

(CMP) - 14 tests - above BMP plus total protein, albumin, alkaline phosphatase (ALP), alanine amino transferase (ALT), aspartate amino transferase (AST), bilirubin

Notes and references

Bibliography

External links

American Association of Clinical Chemistry

Association for Mass Spectrometry: Applications to the Clinical Lab (MSACL)
{{Authority control * Clinical pathology Pathology

Tests

Panel tests

See also

Notes and references

Bibliography

External links