What is a cell culture plate?
A microplate built as housing: treated, sterile, and sized by how much growing surface each well gives the cells.
A cell culture plate is a microplate designed to grow living cells in its wells. It shares the microplate footprint and addressing (127.76 mm by 85.48 mm, ANSI/SLAS), but everything else about it serves the cells: a polystyrene surface plasma treated so adherent cells can attach and spread, sterility suitable for open culture work, a lid that manages gas exchange and contamination, and clear flat wells that go under a microscope. The number that defines any culture plate is its growth area per well, from about 9.5 cm2 in a 6 well plate down to about 0.06 cm2 at 384.
The general microplate concept is covered on the 96 well plate guide; this page defines the culture member of the family.
What makes it a culture plate, not an assay plate
Four things. The surface: tissue culture treatment turns hydrophobic polystyrene hydrophilic and charged, so adhesion proteins and then cells bind; an assay plate surface is specified for optics or protein binding instead. Sterility: culture plates are supplied sterile, typically gamma irradiated, and non-pyrogenic, because they will be opened repeatedly in a hood over days. The lid: culture needs gas exchange without open exposure, so lids are part of the system, where assay plates are usually sealed and done. The optics: wells are clear and flat for microscopy first and readers second; imaging variants trade wall color and bottom thickness around that job.
The formats and their jobs
6 and 12 well (about 9.5 and 3.8 cm2): transfection, larger cultures, work that needs material out of each well. 24 well (about 1.9 cm2): cloning, dose response, microscopy samples. 48 well (about 0.95 cm2): mid-throughput screens and supernatant sampling. 96 well (about 0.32 cm2): endpoint assays, viability and proliferation readouts, the culture format readers are built around. 384 well (about 0.06 cm2): miniaturized endpoint and screening work, where evaporation sets the practical limit. The formats page tabulates growth areas and seeding implications in full.
Culture plate vs dish and flask
Dishes and flasks are for growing cells up: one population, expanded. Plates are for comparing: many small populations under different conditions, read in parallel. Labs use both in sequence, expanding in flasks and seeding plates for the experiment. The scaling unit changes between them: flasks and dishes are chosen by total surface, plates by surface per well, because the well, not the plate, is the replicate.
Related guides
Common questions
Are cell culture plates sterile?
Yes, they are supplied sterile, usually gamma irradiated, and non-pyrogenic, packed with their lids. Sterility lasts until the pack is opened, which is why plates are opened in the hood and handled by their edges.
Can I grow cells in a regular assay plate?
Suspension cells, yes, they grow in the liquid. Adherent cells, no, not properly: on an untreated assay surface they stay rounded, clump, or wash off at the first media change. Adherent work needs a tissue culture treated surface.
What does tissue culture treated mean?
The polystyrene growth surface has been plasma treated so it turns hydrophilic and carries charged groups. Cell adhesion proteins from the media bind to it, and cells bind to them, which is what lets adherent lines attach, spread, and divide instead of floating.
How many cells fit in a well of a culture plate?
It scales with growth area and the cell line: seeding for many adherent lines runs roughly 5,000 to 20,000 cells per well in a 96 well plate (0.32 cm2), scaled up or down by area for other formats and by the confluency the experiment wants. The formats page works through the area math.