1,440 articles
Fluorescence staining
Fluorescence staining attaches fluorescent dyes to specific structures or biomolecules in cells and tissues so they can be visualized under a fluorescence microscope, most often through immunofluorescence.
Fluorescence-based particle tracking
Fluorescence-based particle tracking, usually called fluorescent single-particle tracking (SPT), is a microscopy method that follows individual labeled molecules in living cells, yielding trajectories that reveal diffusion coefficients and molecular interactions.
Fluorescent tagging
Fluorescent tagging is a bench biology method that attaches fluorescent proteins or dyes to biomolecules, letting researchers track their location and dynamics in living cells.
Foam cell
Foam cell: lipid-vacuole-filled macrophage or arterial smooth muscle cell, hallmark of atherosclerotic plaques; forms via scavenger receptor uptake of modified LDL with impaired ABCA1/ABCG1 efflux; SMCs supply roughly half of foam cells.
Folate receptor
Folate receptor: cell surface glycoprotein (FRα, FRβ, FRγ, FRδ) binding folic acid with nanomolar affinity, GPI-anchored, overexpressed 100–300-fold in epithelial cancers; target for folate-conjugated drug delivery and pafolacianine tumor imaging.
Follicular epithelial cell
Follicular epithelial cell (Cell Ontology CL:0000500): an epithelial somatic cell associated with a maturing oocyte; in mammals the granulosa cells of the membrana granulosa, in insects the egg-chamber follicle cells.
Foreskin fibroblast
Foreskin fibroblast, also called human foreskin fibroblast (HFF, FSK) or the BJ line ATCC CRL-2522: primary dermal fibroblasts from neonatal foreskin, used in toxicology, aging, and tissue engineering research; BJ-5ta is the hTERT-immortalized derivative.
FRAP (fluorescence microscopy)
FRAP, or fluorescence recovery after photobleaching, is a fluorescence microscopy technique that bleaches a small region of labeled molecules in a living cell and measures fluorescence recovery to quantify diffusion and binding.
Free-radical theory of aging
Free-radical theory of aging, also called oxidative stress theory, proposed by Denham Harman in 1954–1956: aging results from cumulative free-radical damage, revised in 1972 to a mitochondrial version, now heavily criticized.
FREE1
FREE1 (FYVE1, Q9ASS2) is a plant-specific Arabidopsis ESCRT protein, 601 amino acids, that binds PI3P and ubiquitin, joins ESCRT-I via VPS23, and is essential for MVB sorting, autophagy, ABA signaling, and seedling viability.
Freeze Etching
Freeze etching (freeze-etching): electron microscopy replica technique; frozen specimens are fractured, surface ice is sublimed under vacuum, and platinum-carbon replicas reveal true cell surfaces and membranes, distinct from cryoprotectant-based freeze-fracturing.
Freeze Fracturing
Freeze fracturing (freeze-fracture EM): a TEM sample-preparation method that fractures a frozen biological specimen under vacuum and makes a platinum-carbon replica; key steps are rapid freezing, fracturing, replication, and cleaning, with optional freeze etching.
Freeze substitution
Freeze substitution dehydrates and chemically fixes a frozen biological specimen at low temperature with a solvent such as acetone, producing a resin-embeddable sample for electron microscopy.
FRTL-5
FRTL-5 (FRTL5, Fischer rat thyroid line 5) is a clonal rat thyroid follicular cell line from Fischer 344 rats, TSH-dependent, iodide-concentrating, used in TSH and Graves' autoantibody bioassays; ATCC CRL-8305.
FTC-133
FTC-133 (FTC133, CVCL_1219) is a human follicular thyroid carcinoma cell line from a 42-year-old male, TP53 and PTEN mutant, near-homozygous genome, PAX8/TTF-1 positive, and flown in space on Shenzhou-8 and the ISS.
Fungal cell
Fungal cell: the eukaryotic cell of kingdom Fungi, with a chitin and beta-glucan cell wall, no chloroplasts, glycogen storage, heterotrophic absorption, turgor-driven hyphal growth, and septal pores; distinct from plant and animal cells.
Fusiform gyrus
Fusiform gyrus (gyrus fusiformis): spindle-shaped cortex on the underside of the temporal and occipital lobes, divided by the mid-fusiform sulcus; contains the fusiform face area and visual word form area, and is linked to prosopagnosia and dyslexia.
G-292 clone A141B1
G-292 clone A141B1 (CVCL_2909, ATCC CRL-1423) is a human osteosarcoma cell line from the bone of a 9-year-old White female, fibroblast-like, with a DAXX-KIFC3 fusion, used in bone cancer and drug screening research.
G-361
G-361 (G361; CVCL_1220; ATCC CRL-1424) is a human malignant melanoma cell line from a 31-year-old male's skin, BRAF V600E-mutant, p53 wild-type, used in toxicology, drug-response, and 3D skin model research.
G-401
G-401 (G401, CVCL_0270, ATCC CRL-1441) is a human kidney cancer cell line established in 1975 from a 3-month-old male, long misclassified as Wilms tumor but reclassified in 1993 as rhabdoid tumor of the kidney with homozygous SMARCB1 deletion.
G-402
G-402 (G402, ATCC CRL-1440, Cellosaurus CVCL_1221) is a human epithelial-like kidney cancer cell line from a 9-month-old female, deposited by PT Peebles; hyperdiploid (modal 47), McCoy's 5a culture, used in renal cancer and DepMap research.
G-protein activation
G-protein activation: the GPCR-catalyzed GDP-to-GTP exchange on G alpha that splits the heterotrimer into G alpha-GTP and free G beta-gamma, amplifies signaling, and ends by GTP hydrolysis; Rodbell and Gilman won the 1994 Nobel Prize for its discovery.
G1 Phase
G1 phase, the first gap phase of the eukaryotic cell cycle between mitosis and S phase, where cyclin D–Cdk4/6 phosphorylate Rb to release E2F and the restriction point commits the cell to DNA replication.
G1/S Transition
G1/S transition: the cell cycle commitment point where mammalian cells enter S phase, controlled by pRb-E2F, CyclinD/Cdk4/6 and CyclinE/Cdk2, the Pardee restriction point, and DNA damage checkpoints.
G2 Phase
G2 phase (gap 2) is the cell cycle interval after S phase DNA replication and before mitosis, when the cell synthesizes protein and stockpiles cytoplasm; Cyclin B-CDK1 and G2/M checkpoints govern entry into mitosis.
G2/M Transition
G2/M transition: the cell cycle point where a G2-phase cell commits to mitosis, driven by cyclin B–CDK1 activation and guarded by DNA damage and spindle checkpoints; also the Reactome pathway R-HSA-69275.
GABAA receptor
GABAA receptor: pentameric Cys-loop chloride channel, the brain's main fast inhibitory receptor, built from 19 subunits; target of benzodiazepines, barbiturates, anesthetics, and neurosteroids.
Gamma tubulin
Gamma tubulin (γ-tubulin), tubulin family protein discovered 1989 in Aspergillus nidulans; with GCPs forms γTuSC and γTuRC ring complexes that template microtubule nucleation at centrosomes and non-centrosomal sites; also regulates mitosis, cell cycle, and DNA damage response.
Gap junction assembly
Gap junction assembly: the cellular process building intercellular connexin channels, from ER synthesis and hexameric connexon oligomerization through Golgi and microtubule trafficking to head-on docking and plaque formation (Reactome R-HSA-190861).
GDP dissociation inhibitor
GDP dissociation inhibitor (GDI, RabGDI) is a chaperone protein that binds prenylated, GDP-bound Rab GTPases, extracts them from membranes into cytosolic Rab:GDP:GDI complexes, and recycles them during vesicular trafficking; GDI1 mutations cause X-linked intellectual disability.