United States
Small Molecules Storage and stability
Specific storage and handling information for each product is indicated on the product datasheet. Products are sometimes shipped at a temperature that differs from the recommended storage temperature. Many products are stable in the short-term at temperatures that differ from that required for long-term storage. We ensure that the product is shipped under conditions that will maintain the quality of the product, but save you shipping charges by using the most economical storage conditions for an overnight shipment. Upon receipt of the product, follow the storage recommendations on the product data sheet.
My order arrived at room temperature, but the label on the product says it should be stored at -20°C. Is the product still good?
The storage temperatures that we indicate on our vial labels are the optimal conditions for long term storage. Many compounds are quite stable at warmer temperatures for short periods of time, such as while a package is in transit. If you have concerns about whether or not your item was shipped correctly, the standard shipping recommendation for each product is provided as part of the product listing on our website.
How do I store my peptide?
For maximum stability, store lyophilized peptides desiccated at -20°C. If the peptide is to be weighed out, equilibrate to room temperature in a desiccator prior to opening. Adsorption of water reduces stability and affects sample weight. Changes in temperature during the defrost cycle in a frost-free freezer may reduce peptide stability.
Reconsititued peptides should be aliquotted into individual tubes and stored at -20 or -70°C. Avoid repeated freeze/defrost cycles. In solution, store peptides at pH 5-7 for maximal stability. Peptides in solution have limited stability, especially peptides containing Cys, Met, Trp, Asn and Gln. For maximum stability re-lyophilize reconstituted peptides.
Now that I’ve opened my product and used it for the first time, how should I store the leftover material?
Recommendations for storage after initial use will be provided on the product datasheet that came with your order. These vary depending upon the stability and chemical reactivity of the compound in question. For the majority of compounds, stock solutions in ethanol or DMSO can be stored frozen for up to 3 months.
The datasheet that came with my product says that solutions need to be made fresh and cannot be stored. I do not need to use the entire vial at once, but the amounts are too small to weigh out in solid form.
How can I handle this product so that I do not waste the material?
In many cases such compounds can be dissolved in a volatile solvent, the solution aliquoted in amounts suitable for a single day’s use, and then the solvent evaporated off. This type of method allows you to store the material as very small amounts of solid (far smaller than could be weighed out) which can then be dissolved as indicated on the datasheet when you are ready to use them. If you have questions about whether this technique will work for your situation, or would like help choosing a suitable volatile solvent for the compound you are working with please contact technical support, and we will be happy to provide individual guidance for your particular situation.
My datasheet says that the product needs to be stored under inert gas? What does that mean, and is it really necessary?
Inert gases such as nitrogen or argon are used to protect compounds that are highly prone to oxidation.
To store a material under inert gas, first choose a vial with a tight fitting lid or cap, preferably with either a neoprene stopper or a neoprene gasket to make sure that the seal is as air tight as possible. Aliquot your material as desired then simply use a flexible rubber tube to direct a stream of nitrogen or argon gas down into the vial for few seconds, then cap the vial tightly and seal with parafilm.
(Note: each time a vial is opened and used the nitrogen or argon will need to be replaced before the vial is recapped and returned to storage).
We will only indicate these measures for compounds that are extremely prone to oxidation . These products would have extremely short shelf life without the inert gas.
After I’ve made a stock solution, can that solution be thawed and refrozen for multiple uses, or should it be aliquoted?
Most small molecules are not damaged by freeze/thaw cycles. It is therefore not typically necessary to aliquot stock solutions for stability reasons, although you may do so for convenience if you wish. Unless the product datasheet specifically warns you to avoid repeated freeze/thaw, it is generally safe to freeze and thaw small molecule products as many times as you wish.
Is the product I purchased light sensitive?
The majority of the small molecules we sell are not significantly light sensitive. For those that are, the light sensitivity will be clearly indicated on the product datasheet. It is best to work with light sensitive products in a darkened room, and to either wrap the vials in foil, or keep them in a closed box when they are in storage.
