by tfitzwater » Jun 21 2004 6:35 pm
Precipitation of TBE frequently occurs, especially when a 10x stock is prepared. 5x stocks are more stable according to Maniatis. Autoclaving will retard this reaction. Alternatively, filtration shortly after preparation through a 0.2-0.45 µm cellulose acetate or cellulose nitrate membrane will reportedly allow a 20x stock to be prepared. 30x stocks prepared by this method are stable for 2 weeks. Filtration suggests that nucleation of salt crystals by dust particles or other microscopic insoluble material is responsible for the precipitation problem. If turbidity develops in filtered buffer stocks, autoclaving for 5 minutes at 110°C will remove cloudiness.
Tim Fitzwater
SomaLogic, Inc.