Cryo Coders

Quick Answer: Cryo Coders are small coloured inserts that press into the top of cryovial caps, turning a plain cap into a colour-coded one. Labs use cryo coders to sort frozen vials by project, cell line, passage or owner at a glance, without reading every label in a cold box.

Colour Coding Frozen Vials

Labels on frozen vials are small, frosted and hard to read with gloved hands in the fog above a freezer. A colour on the cap is not. Many cryovials have a recess in the top of the cap made to take a coloured insert, and pressing a coder into it marks the vial with a colour that is visible from above as soon as the box lid is lifted.

Labs agree a colour scheme to suit their work: one colour per cell line, per user, per project or per passage number, or one colour for master stocks and another for working stocks. Because the coder sits in the cap rather than on the vial wall, it adds nothing to the vial’s height or diameter and does not upset the grid positions in the box.

Coders are made for particular cap designs, so they must match the vials in use; an insert made for one cap may sit loose in another. The colours offered and the vial caps these coders fit are not given in the title. Pair them with the vials you actually use, such as the Cryo Vial-Internal Thread, and check that each insert sits flush in its cap.

Using Coders Well

• Fit coders before freezing, while fingers and caps are dry
• Record the colour scheme on the box map and in the freezer log
• Never rely on colour alone; keep a written label on every vial
• Make sure coders sit flush so they do not catch on the box lid

Specifications

Applications

• Separating master and working cell banks in a liquid nitrogen tank
• Marking each student group’s or researcher’s vials in a shared freezer
• Distinguishing clones, strains or passage numbers within one box
• Flagging vials that are due for testing or disposal

Why Choose LabEquip

Coders are usually ordered by cell culture labs, biobanks and teaching labs with shared freezers, often together with vials and boxes such as the Cryo Box (PC), whose clear lid shows cap colours without opening. They are listed in the Biology Lab Products range at LabEquip; ask about colours and compatible vials through our contact page.

Frequently Asked Questions

What are cryo coders used for?

They add a colour to the cap of a cryovial so vials can be sorted by sight. Labs use them to mark cell lines, owners, projects or stock types in freezer boxes.

Will cryo coders fit any cryovial?

No. Coders are made to fit a particular cap recess, and inserts from one design may be loose or not fit at all in another. Match the coders to the vial caps you use and test a few before coding a batch.

Can the coders go into liquid nitrogen?

Coders are made to be stored with their vials at cryogenic temperatures, but check that the insert is rated for the temperature you use and that it stays firmly seated after freezing.

Do the colour inserts replace labels?

No. Colour is a quick sorting aid, but each vial still needs a written or printed label with its identity and date. If an insert falls out, the label is the record that remains.

When should the coders be fitted?

Fit them before the vials are frozen, when caps are dry and at room temperature. Pressing inserts into frozen caps is awkward with gloves and can crack cold plastic.

How many colours should a lab use?

Keep the scheme simple enough to remember, usually a handful of colours with one clear meaning each. Post the colour key on the freezer door and in the freezer log so every user reads it the same way.

Last Updated: September 2026