Molarity counts molecules rather than mass, so two peptides at the same molarity are present in the same number, whatever they weigh. A mass concentration in mg/mL divided by the molecular weight in g/mol gives mol/L directly: 1 mg/mL of a peptide of molecular weight 1,000 is 1 mM.
The molecular weight to use is the free peptide's, and the mass is the mass of peptide rather than of powder, which is the weighed mass multiplied by the net peptide content.
See also
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Cosmic Peptides. (2026, October 30). Molarity: glossary entry. Cosmic Peptides Research Library. Retrieved October 30, 2026, from https://cosmicpeptides.com/research/glossary/molarity
BibTeX
@misc{cosmicpeptides_research_glossary_molarity,
author = {{Cosmic Peptides}},
title = {Molarity: glossary entry},
howpublished = {Cosmic Peptides Research Library},
year = {2026},
month = oct,
url = {https://cosmicpeptides.com/research/glossary/molarity},
urldate = {2026-10-30},
note = {Last reviewed 2026-10-30}
} RIS
TY - ELEC AU - Cosmic Peptides TI - Molarity: glossary entry T2 - Cosmic Peptides Research Library PB - Cosmic Peptides PY - 2026 DA - 2026/10/30 UR - https://cosmicpeptides.com/research/glossary/molarity Y2 - 2026/10/30 LA - en ER -
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