Scintillation Vial

Quick Answer: A scintillation vial is a small screw-capped vial that holds a sample mixed with liquid scintillation cocktail so a liquid scintillation counter can measure its beta radioactivity. Outside radiochemistry, the same vials are widely used for storing small samples and standards.

Glass or Plastic Vials

In liquid scintillation counting, beta particles from the sample excite solvent and fluor molecules in the cocktail, which emit flashes of light picked up by photomultiplier tubes in the counter. The vial therefore has to be transparent to that light, resistant to the cocktail and uniform in shape, so every vial sits in the detector the same way.

Glass vials resist solvent-based cocktails and do not let solvent diffuse through the wall, but ordinary glass contains traces of potassium-40, which adds background counts; low-potassium glass reduces this. Plastic vials, usually polyethylene, give a lower background and do not break, but some cocktail solvents slowly permeate them. The title does not state the material, so confirm glass or plastic and the vial size before ordering.

The cap matters too: a foil or plastic liner helps stop solvent loss and keeps cocktail from creeping up the threads. Clean vials are also a handy size for storing soil and plant extracts, buffers, powders and reference samples, provided they are relabelled clearly and never mixed with vials from radioactive work.

Specifications

Applications

• Counting tritium or carbon-14 labelled samples from uptake or metabolism experiments
• Measuring phosphorus-32 or sulfur-35 in molecular biology and biochemistry work
• Holding filter discs or tissue digests in cocktail for counting
• Storing small quantities of non-radioactive samples and reagents

Care & Handling

• Add the cocktail volume your counter’s protocol specifies and cap tightly before shaking.
• Wipe the outside of each vial before loading, since fingerprints and cocktail on the wall affect counts.
• Let vials stand in the dark before counting if the protocol calls for it, to reduce light-induced background.
• Dispose of used vials and cocktail by the route approved for radioactive and solvent waste.

Why Choose LabEquip

Radiochemistry, pharmacology and plant physiology labs, and teaching labs with a counter, use these vials in quantity. LabEquip supplies them in the Biology Lab Products range, with a scintillation vial rack for bench preparation; state glass or plastic on the contact page.

Frequently Asked Questions

What is scintillation cocktail?

It is a liquid mixture of a solvent and fluors that turns the energy of beta particles into light. Some cocktails accept water-based samples, and newer types use safer, biodegradable solvents.

Why do glass vials give a higher background?

Ordinary glass contains traces of potassium-40, a naturally radioactive isotope, which adds a few counts to every measurement. Low-potassium glass or plastic vials reduce this background for low-activity samples.

Which isotopes can be counted this way?

Liquid scintillation counting is used mainly for beta emitters such as tritium, carbon-14, phosphorus-32, sulfur-35 and calcium-45. It suits low-energy emitters like tritium, which are hard to detect by other means.

Can plastic vials be used with any cocktail?

Not always. Toluene and xylene based cocktails can diffuse into polyethylene and change the counts over time. Use a cocktail recommended for plastic vials, or count soon after preparation.

Can scintillation vials be reused?

Vials from radioactive work are normally discarded as radioactive or solvent waste. Clean, unused vials can serve for general sample storage, but a vial should never move from radioactive use back to general use.

What is chemiluminescence in scintillation counting?

It is light produced by chemical reactions in the vial, for example when alkaline tissue solubilisers react with the cocktail. It adds false counts, so samples are often left in the dark before counting until the extra light fades.

Last Updated: September 2026