Product Storage and Handling
All orders shipped from Haematologic Technologies, Inc. are accompanied by product information sheets which describe proper storage conditions. In order that we may warrant product stability, it is imperative that these storage conditions be maintained at all times. Many of our protein preparations are formulated in 50% (vol/vol) glycerol/H2O which will remain in fluid phase during storage at -20oC. This preferred method of storage yields the greatest protein stability while still allowing access to the stock protein sample without repeated thawing and freezing steps. For some of our new customers who may not be accustomed to handling proteins in glycerol/H2O, here are a few basic tips:
- All products which are formulated with either glycerol/H2O or aqueous buffer are delivered in microcentrifuge tubes. By briefly centrifuging the samples in their original containers, complete recovery of the sample at the bottom of the tube will be accomplished.
- All products which are formulated with glycerol/H2O should be stored at -20oC. Temperatures lower than -30oC should be avoided in order to prevent a phase transition.
- When preparing to make a dilution of the stock sample, remove the sample from storage at -20oC and place on ice for a brief period of time (5-10 min). The sample will become less viscous and thus easier to pipette.
- Never allow protein solutions to remain at room temperature for excessive periods of time. Elevated temperatures may enhance the rate of protein degradation.
- Avoid storing or maintaining dilute protein samples for a long period of time. In general, purified proteins are inherently more stable in concentrated form.
- Many proteins are "sticky" by nature. To avoid losing protein due to adsorption, extremely dilute protein samples should be prepared in buffers containing excipients such as bovine serum albumin, poly(ethylene glycol), or gelatin.