Choosing a 6 well plate without buying the wrong case
At six wells there is one decision that matters, the surface, and it is decided by the cells, not by preference. Everything else is confirmation.
Most wrong 6 well purchases are surface mistakes discovered a week later, when the primary culture never attached or the suspension culture attached and ruined the experiment's premise. This guide walks the surface decision properly, then the confirmations around it.
Start from the job
Name what the well produces. A blot's worth of protein: treated, seeded heavy. A primary culture establishing: coated, per the protocol's named coating. Spheroids or embryoid bodies: non-treated, so nothing attaches. Colonies to pick: treated, seeded sparse. The job names the surface, and the surface names the plate; starting anywhere else buys cases that sit in the store room.
Surface treatment: the adherent versus suspension choice
Tissue culture treated (TC treated) plates have their polystyrene growth surface plasma treated so it wets properly and carries a charge that cells can attach to; adherent cells spread and grow on it. Non-treated plates keep the natural hydrophobic polystyrene surface, so cells cannot attach and grow in suspension instead, which is the entire basis of spheroid and embryoid body work in this format. The rule is short: adherent cells need a treated plate, suspension work needs a non-treated one, and confusing the two wastes the scarcest thing in the lab, the cells themselves. At 6 wells there is no replicate to absorb the mistake.
Coatings: the step beyond treated
Coated plates lay a biological surface over the treated plastic: collagen for many primary and epithelial cultures, poly-lysine for neuronal and weakly adherent cells, and extracellular matrix preparations for stem cell work. Buy the coating the protocol names, from the plate maker where possible, because coating thickness and uniformity are manufacturing variables, and home coating six wells at a time is a known source of well to well variation. Check the storage conditions and shelf life on the case: coatings age, and a coated plate past its date is an untreated plate with a story.
Glass bottom plates, for imaging
Glass bottom 6 well plates swap the polystyrene well floor for a thin sheet of borosilicate glass, usually cover glass thickness at about 0.17 mm, bonded into a polystyrene frame. The point is optical: a molded plastic bottom is too thick and too variable for high numerical aperture objectives, so confocal and high resolution microscopy move to glass. Growth area stays the familiar 9.5 cm2, and the glass can be treated or coated like a culture plate. The trade-offs are price and fragility, and no benefit at all for routine work: at the magnifications most culture watching uses, a standard flat bottom plate is enough.
The confirmations: sterility, lids, and fit
Culture plates are sterile and lidded, always; check only that the lid style matches your handling (standard lids for incubators, and no gimmicks). Fit is nearly universal at this format: the footprint is standard, the height is the shallow culture profile, and stage inserts and carriers accept it. The one fit that varies is the microscope: high magnification work cares about bottom thickness, which is the glass bottom question above, settled before the case is ordered.
Related guides
Common questions
Can I coat a treated plate myself instead of buying coated plates?
You can, and many labs do for routine work, but weigh what varies: coating concentration, incubation, and washing are manual steps, and at 6 wells each plate is a sixth of the experiment. For primary cultures and quantitative comparisons, factory coated plates remove a variable you cannot measure afterward.
Are there glass bottom 6 well plates?
Yes. A glass bottom plate replaces the plastic well floor with a thin borosilicate glass sheet, about 0.17 mm, set in a polystyrene frame, for high resolution and confocal microscopy. Growth area is the same 9.5 cm2. For routine imaging and culture watching, a standard flat bottom plate is enough.
When is 6 wells the wrong choice?
When the experiment is a screen (that is 24 and up), when conditions outnumber six and replicates matter more than material per well, or when the readout is a plate reader assay that gains nothing from big wells. Format follows the limiting resource: conditions, material per well, or access to the well.
How should coated 6 well plates be stored?
Follow the storage conditions and shelf life printed on the case. Coatings age, and a coated plate past its date behaves like an untreated plate, so check the date before seeding a primary culture rather than after it fails to attach. For primary cultures and quantitative comparisons, factory coated plates also remove the well to well variation that home coating six wells at a time introduces.