DEAE-dextran
(50 mg/ml) Dissolve 100 mg of DEAE-dextran (Mr= 500,000; Pharmacia) in 2 ml of distilled H2O. Sterilize the solution by autoclaving for 20 minutes at 15 psi (1.05 kg/cm2) on liquid cycle. Autoclaving also assists dissolution of the polymer.
The molecular weight of the DEAE-dextran originally used for transfection was >2 x 106. Although this material is no longer available commercially, it is still occasionally found in chemical storerooms. The older batches of higher-molecular-weight DEAE-dextran are more efficient for transfection than the lower-molecular-weight polymers currently available.
