PEG-400

PEG-400 (Polyethylene Glycol 400) Research Co-Solvent

PEG-400 (CAS 25322-68-3) is a liquid polyether with an average molecular weight near 400, supplied in a 30 mL bottle as a co-solvent and carrier for laboratory work. Its usefulness comes from sitting between the aqueous and lipophilic worlds: it is fully water miscible while still dissolving many compounds that water alone will not carry, which is why it appears so often in co-solvent systems alongside DMSO.

Solvent Properties & Research Context

• A distribution, not a single molecule. "400" is an average of a chain-length distribution, not a discrete molecular weight. Lots differ slightly in distribution, which matters for viscosity-sensitive or precisely formulated work.

• Water miscible. Dilutes into aqueous buffer without phase separation, unlike a lipid carrier.

• Viscous. Substantially more viscous than water or ethanol at room temperature; allow for slower pipetting and incomplete transfer when measuring small volumes.

• Hygroscopic. Absorbs atmospheric moisture, so water content in an opened container rises over time.

Research Applications

• Co-solvent systems for compounds too poorly soluble for a single vehicle.

• Formulation and solubility screening.

• Vehicle controls at matched final concentration.

Analytical Documentation

Molecular weight distribution and water content vary by manufacturing lot. Kimera Chems does not publish a single fixed purity figure for this item; refer to the batch-specific Certificate of Analysis (COA) issued for the lot received.

Storage & Handling

Store at controlled room temperature. Keep tightly closed.

Storage guidance is a house recommendation. Analytical documentation is per-lot release testing.