What are lab reagents? Types, grades and storage
by Labdrop
A lab reagent is any substance used in the laboratory to prepare, dilute, react with or test other materials. The word covers everything from purified water and simple diluents to acids, bases, buffers and indicators.
The main types
| Type | What it does | Examples |
|---|---|---|
| Solvents and diluents | Dissolve or dilute other substances | Purified water, bacteriostatic water, dilute acetic acid |
| Acids and bases | Adjust pH or take part in reactions | Acetic acid, hydrochloric acid, sodium hydroxide |
| Buffers | Hold a solution at a steady pH | Phosphate and acetate buffers |
| Indicators | Show a property by changing colour | Universal indicator, pH test strips |
Reagent grades
Reagents are sold in grades that tell you how pure they are and how much testing they have had. Analytical reagent (AR) grade and ACS grade are made for analytical work, where impurities would affect results. Laboratory reagent grade suits general lab work and teaching. Technical grade is the least pure and is meant for industrial use rather than analysis. Use the grade your method specifies.
Lot numbers and expiry dates
Each batch of a reagent carries a lot number and an expiry date. Record the lot number when you use a reagent, so a result can be traced back to the batch if a question comes up, and do not use a reagent past its expiry date. Every Labdrop vial carries its lot and expiry on the label, with a QR code that opens the product page.
Storing reagents
Store each reagent as its label says, usually sealed, at the stated temperature and away from light. Keep diluents that look alike clearly marked. We colour-code our caps for this reason: blue for bacteriostatic water and red for acetic acid. Once a vial is opened, follow the discard time on the label, such as 28 days for bacteriostatic water.
Our range
Labdrop supplies lab reagents from UK stock, including bacteriostatic water and 0.6% acetic acid, along with sealed borosilicate vials and pH test strips. For how lab water is graded, see our guide to lab water grades.
Labdrop products are sold for laboratory use only. Not for human or veterinary use.