---
title: "Isoelectric point: research glossary | Sable Peptides"
description: "The isoelectric point (pI) is the pH at which a molecule carries no net electrical charge. For a peptide, it depends on the ionisable N-terminus, C-terminu"
canonical: https://www.sablepeptides.co.uk/glossary/isoelectric-point
publisher: Sable Peptides Limited (UK company 17488610)
note: Research use only. Not for human or veterinary use.
---

Glossary

# Isoelectric point

The isoelectric point (pI) is the pH at which a molecule carries no net electrical charge. For a peptide, it depends on the ionisable N-terminus, C-terminus and side chains. Peptides are often least soluble near their pI, so choosing a buffer pH away from the pI can help dissolve a lyophilised peptide in the laboratory.

Source: [en.wikipedia.org](https://en.wikipedia.org/wiki/Isoelectric_point)

## Related terms

-   [Peptide](/glossary/peptide)
-   [N-terminus](/glossary/n-terminus)
-   [C-terminus](/glossary/c-terminus)
-   [Buffer](/glossary/buffer)

[Back to glossary A–Z](/glossary/terms)

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