Laboratory tools
Peptide Calculator
Work out how much solution to measure after reconstitution. Choose your measuring scale, the peptide in the vial, the water added and the amount you need. Results update as you type and nothing is sent to a server.
Your result
Draw to – mL
–
- Concentration
- –mg/mL
- Volume
- –µL
- Draws per vial
- –
- Per 0.1 mL
- –mg
Laboratory reference only. Volumes are for preparing research solutions; no administration is implied. Check the measured content on the batch certificate of analysis before relying on the label mass.
How the calculations work
Concentration after reconstitution
C (mg/mL) = peptide mass (mg) ÷ diluent volume (mL). 10 mg in 2 mL is 5 mg/mL, which is 5,000 µg/mL or 5 µg per µL. The volume holding a target mass is V = mass ÷ C.
Net peptide content
The label mass and the measured content of a vial can differ. Our certificates of analysis report the measured result; enter measured ÷ label as the net content so the concentration reflects what the lab found.
Dilution and serial dilution
C₁V₁ = C₂V₂. To go from 5 mg/mL to 1 mg/mL in 1,000 µL, transfer 200 µL of stock into 800 µL of diluent. A serial series repeats the same factor from each new tube.
Mass to molarity
M = mass (g) ÷ MW (g/mol) ÷ volume (L). 10 mg of BPC-157 (1,419.5 g/mol) in 2 mL is 3.52 mM. Reverse it to find the mass to weigh for a target molarity.
Isoelectric point and solubility
The pI is the pH at which a peptide's positive and negative charges cancel, where solubility is lowest. Acidic peptides (pI below 6) dissolve best slightly above their pI; basic peptides slightly below.
Concentration by A₂₈₀
Tryptophan (5,500 M⁻¹cm⁻¹) and tyrosine (1,490 M⁻¹cm⁻¹) absorb at 280 nm. A sequence with neither cannot be measured this way; use the HPLC content on the certificate instead.
