Cell biology

Cell polarity

Cell polarity: asymmetric molecular organization defining a polarity axis in cells, driven by PAR, Crumbs, and Scribble modules, Rac/Rho GTPases, and chemical, mechanical, or electrical cues.

Cell proliferation, also called cellular proliferation or cell multiplication, is the increase in cell number through cell growth and cell division; a MeSH descriptor (D049109, 2005) measured in research by DNA synthesis, Ki-67, and related assays.

Cell research

Cell research: study of cell structure and function, grounded in cell theory (Hooke 1665; Schleiden, Schwann, Virchow). Uses microscopy, cell culture, organoids, and mathematical models; in vitro limits and non-animal methods are key themes.

Cell Separation

Cell separation (cell isolation, cell sorting) comprises techniques for separating distinct cell populations, including density fractionation, FACS, MACS, and microfluidic methods, used in immunology, diagnostics, and cell therapy manufacturing.

Cell Shape

Cell shape, the three-dimensional geometry of a cell, is set by cytoskeletal forces, cortical tension, adhesion, and membrane tension, is sensed via geometry cues, regulates function and disease, and evolves in bacteria.

Cell signaling

Cell signaling is how cells communicate chemically: ligands such as hormones, neurotransmitters, and growth factors bind receptors, triggering second-messenger pathways. Forms include paracrine, endocrine, autocrine, synaptic, and contact-dependent signaling.

Cell Size

Cell size: the volume, mass, or dry mass of a cell. Prokaryotes span 0.02–400 µm³, eukaryotes 10–100 µm diameter; diffusion sets the upper limit, enzyme efficiency the lower, and size governs scaling, function, and senescence.

Cell sorting

Cell sorting is a bench biology technique that separates cells from a mixed suspension by physical or fluorescent properties, most commonly by flow cytometry, to produce purified cell populations.

Cell synchronization

Cell synchronization arrests a cultured cell population at a chosen cell cycle stage, or releases it so all cells progress in unison, enabling study of cell cycle-regulated processes.

Cell theory

Cell theory: the principle that all organisms consist of cells, the cell is life's basic unit, and cells arise only from preexisting cells; formulated by Schleiden, Schwann, Remak, and Virchow (1838–1855).

Cell tracking

Cell tracking is a microscopy and image-analysis method that follows individual cells across time-lapse frames, producing trajectories, lineage trees, and measurements of motility and division.

Cell type

Cell type: a category of cells sharing distinctive phenotype and function, e.g. lymphocytes, melanocytes, squamous cells; identified by morphology, marker genes, and transcriptomics, encoded in the genome, cataloged in the Cell Ontology, and central to cancer diagnosis.

Cell viability assay

A cell viability assay is a bench biology method that estimates the proportion of living cells in a culture, usually through a metabolic, dye-based, or ATP readout.

Cell wall

Cell wall: rigid carbohydrate layer outside the plasma membrane of plants (cellulose), fungi (chitin, β-glucans), algae, most bacteria (peptidoglycan), and many archaea (pseudomurein, S-layers); absent in animals and mycoplasmas; prevents osmotic lysis and defines cell shape.

Cell-attached patch clamp

Cell-attached patch clamp is an electrophysiology technique in which a glass pipette seals onto an intact cell, recording single ion channel currents from the membrane patch under the tip.

Cell-extracellular matrix interactions

Cell-extracellular matrix (ECM) interactions: integrin-mediated adhesions such as focal adhesions and hemidesmosomes linking cells to collagen, fibronectin, and laminin, enabling bidirectional signaling, mechanotransduction, motility, survival, and differentiation.

Cell–cell fusion assay

A cell–cell fusion assay measures the merging of two cells' membranes and cytoplasm, using split reporter genes so that reporter activity signals when cell contents mix.

Cellular response to hypoxia

Cellular response to hypoxia: the HIF pathway (HIF-1α, PHD1-3, FIH, VHL), the oxygen-sensing hydroxylation mechanism, its 2019 Nobel recognition, and roles in cancer and inflammation.

Cellular responses to stress

Cellular responses to stress are conserved molecular programs, including the heat shock response, UPR, and integrated stress response, that detect macromolecular damage and decide between repair, arrest, and cell death.

Cellular Senescence (concept)

Cellular senescence: essentially permanent cell cycle arrest with apoptosis resistance and SASP secretion, discovered as the Hayflick limit by Hayflick and Moorhead in 1961; a tumor suppressor, tissue-remodeling program, driver of aging, and senolytic drug target.

Cementoblast

Cementoblast: ectomesenchymal cell that secretes cementum, the mineralized root-covering tissue anchoring teeth; becomes a cementocyte when embedded. Distinct from osteoblasts; regulated by Wnt and TGF-β.

Centrilobular region hepatocyte

Centrilobular (pericentral, zone 3) hepatocytes are liver cells adjacent to the central vein, defined by glycolysis, cytochrome P450 xenobiotic metabolism, glutamine synthesis, Wnt/β-catenin control, and vulnerability to hypoxia and acetaminophen injury.