Tissue Culture Flask

Quick Answer: A tissue culture flask is a flat-sided plastic flask, usually of clear polystyrene with a treated inner surface, in which animal cells are grown attached to the floor or in suspension. Its angled neck and screw cap allow sterile pipette access and controlled gas exchange in a CO2 incubator.

How the Flask Is Built for Cells

Flasks are sized by growth area rather than volume, which is why they are called T25, T75 or T175, the number giving the area in square centimetres; the area of this listing can be confirmed with the order. The flat base lets cells spread as an even monolayer that can be checked under an inverted microscope without opening the flask.

For adherent cells such as fibroblasts or epithelial lines, the inner polystyrene surface is treated, usually by plasma or corona discharge, to make it hydrophilic and charged so cells attach and spread. Untreated flasks are used for suspension cells, which should stay afloat. The product image suggests a treated flask with a filter cap, but check both points when ordering.

The cap controls gas exchange. A vented cap with a hydrophobic filter lets carbon dioxide from the incubator reach the medium while keeping microbes out, so it can stay tight. A plug-seal cap is closed tight for transport or loosened a quarter turn inside the incubator. The canted neck lets a pipette reach the medium without touching the growth surface.

Specifications

Applications

• Growing and expanding mammalian cell lines for research
• Passaging adherent cells with trypsin or other dissociation reagents
• Keeping stock cultures before cells are frozen for storage
• Producing conditioned medium or virus stocks in research labs

Care & Handling

• Work inside a biosafety cabinet and wipe the flask with 70 percent ethanol before it goes in.
• Do not let medium wet a filter cap; a wet filter blocks gas exchange.
• Lay flasks flat in the incubator with the neck slightly raised so medium covers the base.
• Autoclave used flasks and discard them as biohazardous waste.

Why Choose LabEquip

Cell biology research groups, biotechnology courses and vaccine or diagnostic training labs order flasks in quantity. LabEquip includes them in the Biology Lab Products range with multi-well tissue culture plates for experiments; confirm growth area and cap type on the contact page.

Frequently Asked Questions

What does T25 or T75 mean on a culture flask?

The number is the growth area of the flask floor in square centimetres. A T75 flask has three times the surface of a T25 and supports proportionally more attached cells.

Should I use a vented or plug-seal cap?

Vented filter caps are convenient in CO2 incubators because they stay tight while gas passes through the filter. Plug-seal caps give a gas-tight closure for transport or for cells grown without CO2, and are loosened slightly in the incubator.

What is tissue-culture treated plastic?

It is polystyrene whose surface has been modified, usually by plasma treatment, to make it hydrophilic and charged. Adherent animal cells attach and spread well on it but poorly on untreated plastic.

How much medium goes into a culture flask?

Enough to cover the growth surface to a shallow depth; for a T25 flask many protocols use about 5 to 7 ml, with proportionally more for larger flasks. Follow the recommended volume for your cell line.

Can a tissue culture flask be reused?

No. Flasks are sterile single-use items, and polystyrene cannot survive autoclaving for reuse. After use they are treated as biohazardous waste.

Why is the neck of the flask angled?

The canted neck lets a pipette reach the medium at a shallow angle without touching the growth surface, and it reduces the chance of medium running into the cap.

Last Updated: September 2026