Storage and stability, in laboratory terms

Start with the document that belongs to the lot

Compound-specific temperature, light, moisture, and solvent notes belong on the supplier documentation and, when a laboratory has tested the lot, on the certificate of analysis. If those sources disagree with a general habit, follow the lot documents and record which one you used.

Habits laboratories actually write down

• Many lyophilized research peptides are kept cold, often near −20 °C, dry, and out of strong light. That is a common setpoint, not a universal rule.
• After a solid is dissolved, the solution is often split into labeled aliquots so the remaining stock is not thawed over and over. An aliquot here means a labeled laboratory portion, not a quantity for administration.
• Solutions are often held colder than the dry solid. Again, the COA wins when it says otherwise.
• Warm a closed container to room temperature before opening it if the surrounding air is humid, so moisture does not condense into the solid.

What to write on the container

• Compound name and supplier lot.
• Concentration and the unit (mg/mL or mM), solvent, and total volume.
• Date the solution was prepared, and the initials of the person who prepared it.
• Storage location. Do not rely on memory for which vial is the stock.

The concentration line should match a calculation you can repeat. The concentration calculator and the worked arithmetic use the same formulas.

What this page will not do

It will not tell you how long a particular peptide remains within a purity specification, and it will not convert a concentration into a quantity for a person or an animal. Stability claims need data for that compound and that container. A COA is a snapshot of the tests that were run, not a promise about every future use.