CPC Precipitation of Polyanions

Dominik Haudenschild, November 8, 1994 at CBRC

General information and guidelines

Good for selective precipitation of proteoglycans from solution containing proteins

Use 3 parts of CPC to 1 part Polysaccharides by weight.
Keep at least 0.05% free CPC
Polysaccharide concentration should be from 0.1% to 1.0% for optimal results.
Sodium Chloride concentration should be about 0.03M. If there is no Sodium Chloride, add Sodium Sulfate to between 0.02 and 0.04M
Use CPC at room temperature to avoid crystallization.

Specific Protocols

Make solution containing Polyanions 0.03M NaCl by addition of water.

Add 1/7 volume of 10% CPC in 0.03M NaCl

Heat to 40°C for 1 hour to overnight.
If no precipitate is visible yet, add carrier, such as 100µl of 1mg/ml hyaluronic acid.

Allow to cool to room temperature.

Collect by one of 2 methods:
1) filtering onto nitrocellulose then rinsing the nc with 4 volumes 1.4% CPC in 0.03M NaCl
2) Spin out the precipitate at 20,000g at room temperature.
Resuspend precipitated polyanions in 2MNaCl:EtOH (100:15 v/v)
Precipitate again using 2 volumes cold ethanol.