Aseptic Technique
Definition
The handling practices that keep a preparation from being contaminated: disinfecting a stopper before it is pierced, using a fresh needle, and not touching the parts of the equipment that meet the solution. It governs contamination, not sterility, which a container either had or did not.
What this means for research sourcing
Getting this right matters when preparing lyophilized research peptides for in vitro work. Volta ships compounds as lyophilized powder for reconstitution.
Related Terms in Preparation
Vial
The sealed glass or plastic container a peptide is supplied in, closed with an elastomeric stopper under an aluminium crimp. A single-dose vial carries no preservative and is intended to be entered once; a multi-dose vial carries one so it can be entered repeatedly.
Vial Adapter
A fitting that pierces a stopper once and presents a luer connection, so a syringe can be attached without a needle passing through the closure again. It reduces coring of the stopper on repeated entries.
Aliquot
A measured portion divided out of a larger volume. Splitting a reconstituted solution into single-use aliquots is how repeated freeze-thaw of the whole stock is avoided, and it is the standard answer to a material that degrades on repeated freeze-thaw.
Working Stock
A diluted solution prepared from a concentrated one for day-to-day use, so the concentrated stock is disturbed as rarely as possible. The dilution factor and the date belong on the label, because a working stock is the thing most likely to be misidentified later.
Excipient
Anything in a formulation other than the active substance: bulking agents, buffers, preservatives, stabilisers. Excipients decide how a cake looks and how well it redissolves, and they appear on an approved label alongside the active.
Mannitol
A sugar alcohol used as a bulking agent and cryoprotectant in freeze-dried formulations. It gives the cake its visible structure and shields the peptide during drying, so a vial that looks empty often simply has no mannitol in it.
Peptide Blend
One vial holding two or more compounds pre-mixed at a fixed ratio by the supplier, as against a stack, where each compound has its own vial. A blend's certificate reports each component separately and states no single purity for the vial.
Enteric Coating
A polymer film on a capsule or tablet that holds together in stomach acid and dissolves at the higher pH of the small intestine. Oral peptide formulations use it to get past gastric proteases, with limited success for anything but short sequences.