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Pharmacological Reagent FAQs

Here you’ll find answers to the most frequently asked questions regarding venom toxins, neurotrophins, pro-neurotrophins, and growth factors. This should help you get the most out of these powerful and versatile tools. If you have any other questions or would like some advice on how best to use these reagents, please get in touch with our technical support team, who will be happy to help.

Are peptides from natural or synthetic sources?

Alomone Labs proteins/peptides are derived from three main sources: recombinant (expressed in E. coli), synthetic peptides or natural (isolated from the original source in nature). The source of each peptide or protein is specified for each product.

Are additives added to the peptides/proteins?

Our peptides/proteins are lyophilized from distilled water or any volatile buffer with a minimum amount of salt. Carrier proteins or other additives (e.g., BSA, HSA, sucrose, etc.) are not added.

How to store and handle reagents?

Reagents are shipped at room temperature in a stable lyophilized form. Upon receipt, store the products at -20°C. Protect from moisture.
Upon reconstitution, the solution can be stored at 4°C for up to 1 week. For long-term storage of a reconstituted solution, divide the stock solution into small aliquots and store at -20°C*. Aliquoted vials can be stored at -20°C for at least 6 months. Upon use, thaw the relevant vial and dilute it in your working buffer.
We do not recommend storing reconstituted reagent in a working solution for longer than a few days.
Note: Avoid multiple freeze-thaw cycles.
Note: For long-term storage of diluted solutions of neurotrophins, pro-neurotrophins and growth factors – consider adding 0.1% bovine serum albumin (BSA).
*For stock solution preparation, follow the detailed instructions below.

What is the expiration date of peptides/proteins?

Under proper storage conditions, proteins/peptides tend to be stable for many years. These conditions include storing proteins as lyophilized powder, storing the product frozen (-20°C or -80°C) at protein concentrations of greater than 0.1 mg/ml in DDW or low salt concentration, and limiting the number of freeze/thaw cycles.

How do I store my neurotrophins, pro-neurotrophins, and growth factors?

For long-term storage, divide the stock solution into small aliquots and store at -20°C. Aliquoted vials can be stored at -20°C for at least 6 months. Upon use, thaw the relevant vial and dilute it in your working buffer. The reconstituted solution can be stored at 4°C for up to 1 week. We do not recommend storing the product in a working solution for longer than a few days. For long-term storage of diluted solutions, consider adding 0.1% bovine serum albumin (BSA). Avoid multiple freeze-thaw cycles. We recommend preparing fresh solutions for working buffers before each use.

How to reconstitute reagents?

1.       Reagents are shipped at room temperature in a stable lyophilized form. To spin down all the powder to the bottom of the vial, centrifuge vials (10,000 x g, 5 minutes) before adding any solvent.
Note: The lyophilizate may be difficult to visualize in the vial.
2.       Follow product-specific instructions for selecting the preferred solvent solution**.Add your solvent directly to the centrifuged vial and tap on it to dissolve the lyophilized reagent.
3.       Tilt and gently roll the liquid over the walls of the vial.
Important! For toxins and peptides – avoid vigorous vortexing (up to 3 seconds of light vortexing is enough). For neurotrophins, pro-neurotrophins, and growth factors – we recommend completely avoiding vortex.
4.       Spin down and divide the solution into single-use aliquots.Store the aliquots at -20°C.
5.       Before use, thaw the vial and dilute the reagent in working buffer.
**Venom toxins are usually soluble in pure water (e.g., double-distilled water (ddH2O)) at high micromolar concentrations (0.1–1 mM). You can typically reconstitute the lyophilized product in any aqueous buffer. Yet, we highly recommend preparing a stock solution in pure water, unless stated otherwise in the product datasheet. For neurotrophins, pro-neurotrophins, and growth factors, our general recommendation is to reconstitute with sterile water at a concentration of 0.01–0.1 mg/mL as a stock solution. You can further dilute the stock solution as needed.
Note: We recommend preparing fresh working buffers before each use.
Note: Avoid multiple freeze-thaw cycles to maintain biological activity.
Note: Avoid heating peptides/proteins. Work at ambient room temperature and no higher than 37oC.

How to reconstitute a dimethyl sulfoxide (DMSO)-soluble toxin?

Some toxins and peptides are soluble in DMSO; you can find this information in the product specification section. For these products, prepare a concentrated stock solution first.
1.       Centrifuge vial (10,000 x g, 5 minutes) before adding solvent.
2.       Dissolve the lyophilized reagent in DMSO. We recommend keeping a concentrated stock solution at 1-10 mM (100-1000X higher than the final working concentration).
3.       Once the peptide is completely dissolved in DMSO, slowly dilute the peptide in pure water (or buffer) to the desired final working concentration.
Note: We recommend that you maintain a DMSO concentration as low as possible. For cell assays, a final concentration of 0.1–0.5% DMSO (v/v) is considered acceptable. For other experiments, 5% DMSO (v/v) is recommended; adjust this according to your experimental requirements.

What toxin stock concentration should I prepare?

Usually, your stock concentration should be 100–1000X higher than the working concentration. We do not recommend storing the toxin at your final working concentration.

How do I reconstitute my neurotrophins, pro-neurotrophins, and growth factors?

To spin down all the powder to the bottom of the vial, it’s important to centrifuge reagents (10,000 x g, 5 minutes) before adding any solvent.
From our experience, you should reconstitute neurotrophins, pro-neurotrophins, and growth factors with sterile water at a concentration of 0.01–0.1 mg/mL as a stock solution. You can further dilute the stock solution as needed.