287 articles
Biomarker
A biomarker, or biological marker, is an objectively measured characteristic indicating healthy biological activity, disease, or response to an exposure or treatment; examples include blood glucose and blood pressure.
Blood culture
Blood culture: laboratory incubation of patient blood in aerobic and anaerobic broth bottles to detect bacteremia and fungemia; 20–30 mL per adult set, automated CO2 detection since the 1970s BACTEC era, still the reference standard over rapid molecular assays.
Blood film
A blood film, or peripheral blood smear, is blood spread on a stained glass slide and examined under a microscope to assess blood cells and detect parasites.
Blood gas testing
Blood gas testing, also called blood gas analysis, is a laboratory test measuring blood pH, carbon dioxide, and oxygen to assess ventilation, oxygenation, and acid–base status.
Blood glucose monitoring
Blood glucose monitoring is the measurement of glucose in blood or interstitial fluid, using laboratory tests, fingerstick meters, and continuous glucose monitors to guide diabetes diagnosis and insulin dosing.
Blood smear
A blood smear is a test in which a thin layer of blood is spread on a slide, stained, and examined microscopically to evaluate blood cells and detect parasites.
Blood test
A blood test, also called blood work or blood analysis, is a laboratory test measuring cells, chemicals, and proteins in blood, often part of a regular checkup.
Blood typing and crossmatching
Blood typing and crossmatching are the laboratory procedures that establish a patient's ABO and Rh blood group, screen for antibodies, and confirm donor blood compatibility before transfusion.
Bone histomorphometry
Bone histomorphometry is a quantitative microscopy method measuring bone structure, cellular activity, and formation and resorption rates in an undecalcified bone biopsy, usually from the iliac crest.
BRAF rearrangement analysis
BRAF rearrangement analysis is molecular diagnostic testing that detects BRAF gene fusions in tumor tissue, found especially in pilocytic astrocytoma, to support cancer diagnosis and guide RAF- or MEK-directed therapy.
Breath test
A breath test measures gases in exhaled breath to detect disease, chiefly the urea breath test for H. pylori and hydrogen tests for malabsorption and SIBO.
Cancer genetics
Cancer genetics: the medical field studying genetic and genomic factors in cancer, split into somatic tumor testing and germline risk-allele testing; also the Elsevier journal Cancer Genetics, ISSN 2210-7762, continuing Cancer Genetics and Cytogenetics since 2011.
Cannabis drug testing
Cannabis drug testing detects THC or its metabolite 9-carboxy-THC in urine, oral fluid, blood, hair, or breath; urine immunoassay screens at 50 ng/mL, HHS confirms above 15 ng/mL, and results show exposure, not impairment.
Capillary blood sampling
Capillary blood sampling collects a small blood sample, usually under 1 mL, by pricking the fingertip, heel, or earlobe, and is widely used in newborn screening and self-monitoring.
Carbapenem inactivation method
The carbapenem inactivation method (CIM) is a low-cost phenotypic assay that detects carbapenemase production in Gram-negative bacteria using a meropenem disk and an E. coli indicator strain.
Carbohydrate-deficient transferrin measurement
Carbohydrate-deficient transferrin (CDT) measurement is a blood test detecting chronic heavy alcohol consumption, rising after roughly 40–60 g ethanol daily and normalizing within weeks of abstinence.
Carcinoembryonic antigen
Carcinoembryonic antigen (CEA), a glycoprotein tumor marker discovered by Gold and Freedman in 1965 at McGill, is used mainly to monitor colorectal cancer treatment and recurrence, not for screening.
Carrier testing
Carrier testing is a genetic test that identifies carriers of one recessive or X-linked disease variant and estimates the risk of an affected child, ideally before conception.
Cell-free DNA analysis
Cell-free DNA analysis detects short DNA fragments circulating freely in blood and other body fluids, used in prenatal screening, cancer detection and monitoring, and transplant surveillance.
Cell-free DNA screening
Cell-free DNA screening is a noninvasive prenatal test that analyzes fetal DNA fragments in a pregnant woman's blood to screen for chromosomal abnormalities such as trisomy 21.
Cerebrospinal fluid analysis
Cerebrospinal fluid analysis is a diagnostic test in which CSF, usually obtained by lumbar puncture, is examined for cells, protein, glucose, and pathogens to diagnose central nervous system disease.
Chemiluminescent assay
A chemiluminescent assay is a laboratory method that measures hormones, antibodies, or tumor markers through light emitted by a chemical reaction, first reported in 1978.
Chemiluminescent immunoassay
Chemiluminescent immunoassay (CLIA) is a laboratory diagnostic method that detects antigens or antibodies using a light-emitting label; first reported in 1985, it displaced radioimmunoassay and is fully automated.
Chromogenic in situ hybridization
Chromogenic in situ hybridization (CISH) is a pathology technique that detects specific DNA or RNA sequences in tissue sections, introduced in 2000 for HER2 testing in breast cancer.
Chromosomal analysis
Chromosomal analysis is a cytogenetic diagnostic method that examines chromosome number and structure, most commonly by G-banded karyotyping, to detect abnormalities such as aneuploidy and translocations.
Chromosomal microarray analysis
Chromosomal microarray analysis (CMA) is a genetic diagnostic test using DNA microarrays to detect chromosomal deletions and duplications genome-wide, the recommended first-tier test for developmental delay, autism, and congenital anomalies.
Chromosome analysis
Chromosome analysis is a cytogenetic laboratory method that examines the number and structure of chromosomes in dividing cells, most commonly by G-banded karyotyping, to diagnose constitutional and acquired chromosomal disorders.
Circulating tumor DNA analysis
Circulating tumor DNA analysis is a liquid biopsy method that detects tumor-derived DNA fragments in blood to guide cancer treatment, monitor recurrence, and screen for cancer.
Circulating tumor DNA detection
Circulating tumor DNA (ctDNA) detection is a blood-based diagnostic method that measures tumor-derived DNA fragments in plasma to genotype cancer non-invasively, assess treatment response, and detect molecular residual disease after therapy.
Clinical biochemistry
Clinical biochemistry (clinical chemistry, chemical pathology): laboratory discipline analyzing blood, urine, and CSF for metabolites, hormones, electrolytes, and enzymes; rooted in Wöhler's 1828 urea synthesis; central to diagnosis, monitoring, and evidence-based laboratory medicine.