Research resources
Tools and reference for the bench.
A concentration calculator, handling notes for lyophilized materials, and the vocabulary we use on labels.
Tool
Reconstitution & concentration calculator
Concentration, molarity and aliquot volume from the amount in the vial and the diluent volume.
- Concentration
- —
- Same, per µL
- —
- Molarity
- —
- Volume per aliquot
- —
- Aliquots per vial
- —
Arithmetic only. Actual fill can differ from nominal.
Handling lyophilized materials.
- 01
Equilibrate first
Let a sealed vial reach room temperature before opening, so moisture doesn't condense on the lyophilized cake.
- 02
Add diluent slowly
Run the diluent down the inside wall of the vial and swirl gently. Vigorous shaking can promote aggregation.
- 03
Choose the diluent for the assay
Solubility and diluent choice depend on the compound and on your experimental design — check the literature.
- 04
Aliquot once
Split reconstituted material into single-use aliquots so it isn't frozen and thawed repeatedly.
- 05
Label everything
Record compound, concentration and date on every aliquot.
Glossary.
- Lyophilized
- Freeze-dried. Water is removed under vacuum, leaving a dry powder or cake that is stable in storage.
- Reconstitution
- Returning lyophilized material to solution by adding a measured volume of diluent.
- CAS number
- A unique registry identifier assigned by the Chemical Abstracts Service to a specific substance.
- Molecular weight
- Mass of one mole of the compound, in g/mol. Needed to convert mass concentration to molarity.
- Research use only (RUO)
- Supplied for laboratory research. Not for human consumption, diagnostic or therapeutic use.
Published literature
For mechanism and methodology, search the primary literature on the compound of interest in PubMed. We do not provide use guidance of any kind.