Definition
Dissolving a lyophilised peptide in a chosen diluent to produce a solution of known concentration.
Reconstitution returns a lyophilised peptide to solution. The diluent is chosen from the sequence and the intended assay: sterile water, bacteriostatic water, dilute acetic acid for basic or hydrophobic peptides, or a small volume of DMSO for very hydrophobic sequences. Concentration in mg/mL equals peptide mass in milligrams divided by diluent volume in millilitres; because 1 mg/mL equals 1 µg/µL, the volume holding a given mass follows directly. For example, 10 mg in 2 mL gives 5 mg/mL, so 250 µg is in 50 µL. Diluent is added slowly down the vial wall and the vial swirled gently, never shaken, to limit aggregation.