Hexadimethrine bromide
Hexadimethrine bromide is a cationic polymer used to increase the efficiency of transduction of certain cells with retrovirus in cell culture. Hexadimethrine bromide acts by neutralizing the charge repulsion between virions and sialic acid on the cell surface. Use of Polybrene can improve transduction efficiency 100-1000 fold although it can be toxic to some cell types. Polybrene in combination with DMSO shock is used to transfect some cell types such as NIH-3T3 and CHO. It has other uses, including a role in protein sequencing.
In the 1950s and 1960s, hexadimethrine bromide was used to reverse heparin anticoagulation during open-heart surgery. It was supplanted for this use by protamine sulfate, after administration of large quantities of hexadimethrine bromide was found to cause kidney failure.
Polybrene is also used in enzyme kinetic assays in order to reduce spontaneous activation of zymogens that are prone to auto activation.
