Media Terminology Guide

Basal Medium		Medium lacking growth supplements. Selected to control timing & amount of supplements added in order to make complete Growth or Culture Medium.  With a shelf life of 1 year, some researchers also select BM if anticipating long storage periods between experiments.
Classical Medium		DMEM, MCDB-105, RPMI-1640.  Ready-to-use, time-proven standbys that form a sound foundation for in vitro culture experiments.  Often selected for cell lines, which generally thrive in broadly standard culture conditions, but not typically recommended as-is for more media-selective and finicky primary cells.
Conditioned Medium		Contains cell-secreted, bio-active growth factors, proteins & cytokines, a.k.a. "Cell-free culture supernatant."  For particularly fastidious or finicky cells that require specific mediator substances to help them grow or "take."
Corne-Epi Medium		Serum-free medium, with ingredients and supplements optimized for the unique requirements of corneal epithelial cells, providing optimal culture conditions, cell health, data integrity and reproducibility.
Cryopreserved Cell Total Kit		Contains a cryovial of frozen cells, plus all corresponding Media and Subculture Reagents.
Culture Medium		While their names are similar and both arrive all-in-one, pre-mixed & ready-to-use, Culture Medium differs from Growth Medium in an important aspect. Whereas GM is used for cells that proliferate (divide), Culture Medium provides favorable, precise, controlled conditions for the smaller sub-set of non-dividing cells. It is thus employed to maintain or experiment on non-proliferative cells like neurons, B & T Cells, mononuclear cells and other blood cells.
Culture Supplements		Concentrated proteins, factors, cytokines, serum (or serum-free alternatives) and nutrients added to Basal Medium to make complete Culture Medium.
Defined Medium		Contains known components, defined chemically & by concentration. Serum is absent or replaced by specific growth factors. May contain animal-derived albumin, transferrin, etc.
Dissociation Medium		Calcium- and Magnesium- free subculture reagent containing metal ion chelator ethylenediaminetetraacetic acid (EDTA) in phosphate buffered saline. Use as an alternative to Trypsin/EDTA when passaging Induced Pluripotent Stem Cells (iPSC)
Differentiation Medium		Medium formulated to change cells to a type that is more specialized in form & function. Used to differentiate skeletal muscle cells, chondrocytes, osteoblasts, preadipocytes, etc.
EpiVita Medium		Media optimized to increase population doublings of in vitro-cultured Human Epidermal Keratinocytes and many Epithelial Cells. The formulation can boost the duration of experiments requiring additional completion time.
Freezing Medium		Basal medium containing a cryoprotectant like DMSO and serum (or a serum alternative). Creates cell stocks and stores cells long-term in liquid N2, with optimal cell survival, viability & recovery upon thawing.
Growth Medium		All-in-one, ready-to-use media containing pre-added growth supplements optimized to the unique needs of each cell type.  Induces robust cell growth and proliferation.  No mixing is needed and in many cases, GM is the medium you will select for general cell growth.  Shelf life is typically 6 months.
Growth Medium Kit		Basal medium & growth supplement sold together packaged separately, to control the timing and/or amount of supplements added, and to extend shelf life to 1 year.
Growth Supplements		Concentrated growth factors, cytokines, serum (or serum-free alternatives) and nutrients added to Basal Medium to make complete Growth Medium.  The entire volume of the GS is added to the corresponding bottle of Basal Medium to make the GM.  In some cases, Supplements may be separated into individual bottles or vials to ensure performance and eliminate precipitation.  Due to the unique needs of each cell type, the volume of GS can vary from as little as 2.5 ml to as much as 50 ml. Because they are concentrated and most GS can be frozen for a year, some lab workers select the separate GS to extend shelf life for prolonged storage periods.
Induction Medium		Provides signals that alter cells or “induce” changes to cell behavior, shape, differentiation, mitotic activity, signal cascades or gene expression.
Maintenance Medium		Formulated to preserve cells in a specific state.  Retains phenotype without inducing differentiation, such as with hepatocytes, adipocytes or stem cells.
Plating Medium		Enhances attachment of cells to surface. Facilitates the culture of neurons or other cells that require specific conditions or additives to lay down and adhere.
Serum-Free Medium		Medium lacking fetal bovine serum (FBS), horse serum or other sources. Select this for protocols that require optimized medium definition, lot-to-lot consistency and control, while maintaining cell performance, growth & productivity.
Starvation Medium		Medium lacking serum, nutrients &/or key growth factors. Choose Starvation Medium when cells need to be deprived prior to the experiment or treatment, or to synchronize cell cycle.
Xeno-Free Medium		Chemically-defined medium devoid of animal- or human-derived components.  For stem cell expansion or other uses that must avoid variability due to undefined animal components.  Choose when media must be entirely free of animal-derived components, serum & albumin, replaced with recombinant or synthetic growth factors, amino acids, vitamins, lipids, insulin, etc.