45 articles
AIDS Serodiagnosis
AIDS serodiagnosis: laboratory and point-of-care diagnosis of HIV infection by antibody or p24 antigen testing, from the 1985 ELISA to fourth-generation Ag/Ab assays, CDC algorithms, and rapid-test sensitivity limits.
Aspartate aminotransferase to platelet ratio index
The aspartate aminotransferase to platelet ratio index (APRI) is a noninvasive formula combining AST and platelet count to estimate liver fibrosis, reported in 2003.
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.
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.
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.
Companion diagnostic
A companion diagnostic is an in vitro test essential for the safe, effective use of a specific drug, identifying patients likely to benefit or suffer serious adverse reactions.
Counterimmunoelectrophoresis
Counterimmunoelectrophoresis (CIE), also called counter-current immunoelectrophoresis, is a serological technique in which an electric field drives antigen and antibody together in a gel, forming a visible precipitin line.
Creatinine clearance
Creatinine clearance (CrCl) is a kidney function test estimating glomerular filtration rate from blood and 24-hour urine creatinine; it overestimates true GFR and has largely been replaced by eGFR equations.
Cross Reactions
Cross Reactions (cross-reactivity): serological reactions where an antiserum against one antigen also reacts with a closely related, non-identical antigen; basis of allergy cross-reactivity, immunoassay interference, and serology false positives.
Cytodiagnosis
Cytodiagnosis is the diagnosis of disease by microscopic examination of individual cells, clusters, and tissue fragments from body fluids, scrapings, and fine-needle aspirates, usually confirmed by biopsy.
Digital ELISA
The single-molecule array (Simoa) is a digital ELISA technology commercialized by Quanterix that counts individual enzyme-labeled protein complexes in femtoliter wells, roughly 1,000-fold more sensitive than conventional immunoassays.
Direct agglutination test
The direct agglutination test (DAT) is a serological assay that detects anti-Leishmania antibodies in serum by visible clumping of stained parasites, used mainly to diagnose visceral leishmaniasis.
Direct antiglobulin test
The direct antiglobulin test (DAT) is a blood test detecting antibody or complement proteins bound to red blood cells, used to diagnose immune hemolytic anemia and transfusion reactions.
DNA ploidy analysis
DNA ploidy analysis is a cytometric method measuring the DNA content of individual cells by flow or image cytometry to detect aneuploidy in cancers and estimate the S-phase fraction.
Ecarin clotting time
The ecarin clotting time (ECT) is a coagulation assay using ecarin, venom of the saw-scaled viper, to measure direct thrombin inhibitors such as dabigatran and hirudin.
ERG rearrangement analysis
ERG rearrangement analysis is a molecular diagnostic test that detects ERG gene rearrangements, most often the TMPRSS2–ERG fusion, to support prostate cancer diagnosis and risk stratification.
Exfoliative cytology
Exfoliative cytology is the microscopic examination of cells shed or scraped from body surfaces to detect infections, hormonal changes, and precancerous or cancerous lesions, best known through the Pap test.
False-positive serological test for syphilis
False-positive serological test for syphilis (biologic false positive, BFP; ICD-11 MA14.16): a reactive nontreponemal test such as RPR or VDRL caused by conditions other than syphilis, including autoimmune disease, HIV, malaria, pregnancy, and vaccination; occurs in roughly 0.2%–0.8% of the population and is resolved by confirmatory treponemal testing.
FibroTest
FibroTest is a blood test combining five serum biomarkers, adjusted for age and sex, into a score estimating liver fibrosis stage, a noninvasive alternative to biopsy.
Fluorescent enzyme immunoassay
A fluorescent enzyme immunoassay is an immunoassay, a variant of ELISA, in which an enzyme-labeled antibody converts a substrate into a fluorescent product for sensitive detection.
Fluorescent Treponemal Antibody-Absorption Test
FTA-ABS (fluorescent treponemal antibody-absorption) test: manual treponemal syphilis serology using fluorescein-labeled antibody and Reiter treponeme absorption; developed 1957–1964; CDC now prefers TPPA.
Georges-Fernand Widal
Georges-Fernand Widal (1862–1929) was a French physician and bacteriologist at Hôpital Cochin in Paris who introduced the typhoid agglutination test in 1896 and helped immunize the French army against typhoid.
Hemagglutination
Hemagglutination is the clumping of red blood cells by antibodies, lectins, or viral proteins such as influenza hemagglutinin binding sialic acid; it underlies blood typing and the hemagglutination inhibition assay used for influenza serology.
Hemagglutination Tests
Hemagglutination tests (HA, HI/HAI, Hirst test) detect and quantify viruses or antibodies by visible clumping of red blood cells via viral hemagglutinin; used for influenza diagnosis, vaccine antigenic characterization, and blood group typing.
High-resolution melt analysis
High-resolution melt analysis (HRM, also HRMA) is a closed-tube real-time PCR method that detects DNA variants, genotypes SNPs, and estimates methylation without sequencing or labeled probes.
Immunofixation electrophoresis
Immunofixation electrophoresis (IFE) is a clinical lab technique that identifies and types monoclonal immunoglobulins in serum, urine, or CSF, the IMWG gold standard for confirming monoclonal proteins.
Immunologic Pregnancy Tests
Immunologic pregnancy tests detect hCG in urine or serum using antigen-antibody reactions, beginning with the 1960 Wide-Gemzell hemagglutination inhibition test and evolving through RIA, latex agglutination, and enzyme immunoassay into modern home tests.
Immunologic Tests
Immunologic tests, also called immunodiagnosis or serologic tests, are antibody-antigen-based diagnostic assays, spanning ELISA, radioimmunoassay, agglutination, and lateral flow immunoassay formats used for pregnancy, infection, hormone, and drug detection.
Immunoturbidimetry
Immunoturbidimetry is a homogeneous immunoassay technique that quantifies analytes such as serum proteins by measuring the turbidity, or loss of transmitted light, from antigen-antibody complexes, and runs on automated clinical chemistry analyzers.
Karyotype analysis
Karyotype analysis is a cytogenetic test that examines the number and large-scale structure of chromosomes in dividing cells, diagnosing conditions such as Down syndrome, Turner syndrome, and leukemia-related abnormalities.