Biochemical & small molecule technical FAQs
Using your product safely
Using your product
- How to dissolve your product
- Molecular weight and molecular formula
- How to use NaOH equivalents to make up solutions
- Do you need to re-weigh your product?
- Cell permeability
- What dose of small molecule biochemical should I use in vitro?
- What dose of small molecule biochemical should I use in vivo?
- What is the best solvent to use in vivo?
Storing your product & product stability
- How to store your product
- Storing as a solid
- Storing and working with solutions
- How your product is shipped
Your product’s appearance
- What your product should look like
- What to do if you can't see any product
- Do different batches look the same?
Using your product safely
We also supply you with SDS’s (safety datasheets) with all of our products. These provide you with advice on how to safely handle your product. It is your responsibility to ensure that all relevant safety precautions are taken at all times, as due to the nature of our products the potential hazards are not always known.
Using your product
To help you dissolve your product, you can find instructions on your product’s datasheet (we always supply these with each order) or you can also find them on our website. Temperature is very important when solubilising your product. For example if you’ve cooled or frozen your solution, your product may have precipitated out of solution. So here’s an important rule – make sure you check that your product is fully re-dissolved before use.
Solubilising (or dissolving) your product can sometimes be tricky! Here are a few tips and tricks from our scientists to help you out:
Once your product is in suspension, to help solubilise your product you can try:
- Stirring – try rapidly stirring or vortexing in a whirlimixer
- Heating – try warming it gently in a water bath
- Sonicating – sonication may also be worth a try
The molecular weight on our website and the product label represents the molecular weight of the compound as depicted in its chemical structure. However, due to water composition, or due to a change of salt, molecular weights can vary slightly from batch to batch. You should therefore use the batch specific MW which is found on the certificate of analysis which accompanies the compound.
If you’re working with amino acids, you might sometimes find these quite difficult to solubilise. If this is the case you can often make up solutions using NaOH equivalents to help. Our data sheet should help you decide if this would be appropriate.
NaOH equivalents often fill researchers with dread but don’t worry - we’ve written a simple explanation below to help you out:
If you use this formula you can calculate the volume of NaOH (aq) of concentration needed to dissolve your product in 1 equivalent of NaOH(aq):
= Product mass (mg) x 1000 .
Molecular weight x Concentration of NaOH (mM)
= Volume of NaOH (mL)
= 10mg x 1000 .
Molecular weight (eg. 235) x 100mM
= 0.426 mL
You should weigh out the quantity of product that you require for your experiment as the amount of product in our vials isn’t weighed out accurately enough for direct addition of solution. This excludes 1mg units which are supplied as a lyophilized solid. For these packs, solutions should be made by directly adding solvent to the vial. You should then vigorously vortex the vial to ensure the product has been completely dissolved.
If a product is cell permeable we’ll try and let you know in the product description.
As a rough guide, charged molecules tend not to be cell permeable, whereas phosphorylated compounds may well be. Large peptides also tend to struggle crossing cell membranes but some peptide modifications (eg. TAT) will help.
When trying to calculate this, we recommend that you survey the literature to check for key values – IC50, EC50 or Ki. If published values are known, we recommend that you use 5 to 10 times higher than these values. This should allow you to maximally inhibit your target, such as a receptor or enzyme’s activity.
If you are unable to find published values, you should perform dose-response experiments and use Michaelis-Menten kinetics to calculate Ki values.
Many factors such as incubation period, whether your product is cell permeable and the type of cells or assay being used in an experiment can affect the amount of product required.
This depends on many complex factors. You should review published literature for guidelines on dosage as we do not carry out in vivo biological testing of our products.
There are a number of factors to consider when deciding on a solvent for use in vivo. These include characteristics of the compound of interest (polarity, solubility, stability, temperature etc) and also the route of administration, dose, species to be used, and age and mass of the animal.
Water or saline are the preferred solvents for hydrophilic compounds.
DMSO (dimethyl sulfoxide) is a widely used solvent for hydrophobic compounds but should be present in concentrations of less than 0.1% for most applications as toxicity effects can occur at higher concentrations. Ethanol can also be used and for extremely hydrophobic compounds vegetable oil or polymer preparations of cyclodextrin (CD), carboxymethyl cellulose (CMC), or polyethylene glycol (PEG) can be suitable vehicles.
Prior to use, the solvent should always be assessed for toxicity, and vehicle-ony controls incorporated into experiments.
The following references may also be useful:
Maeset al (2012) Evaluation of 14 Organic Solvents and Carriers for Screening Applications in Zebrafish Embryos and Larvae. PLoS ONE, 7(10), p.e43850.
Galvao et al (2013) Unexpected low-dose toxicity of the universal solvent DMSO FASEB J 2014 Mar;28(3):1317-30
How to store your product
Due to the nature of our products there isn’t much information on long-term product stability. However, as part of our Hello BioPromise we regularly carry out stability tests to ensure that products are still stable.
To properly store your product, you should always check the product datasheets that we include with your product, there will be specific recommendation there for your product.
As a general guide we recommend the following when storing your product:
If you keep the vial tightly sealed and follow the instructions on the product vial, you can store the product for up to 6 months. Due to the hydroscopic nature of some products, products stored at below ambient temperature should be allowed to warm to ambient temperature prior to opening.
We also recommend preparing and using your solutions on the same day. However, if this isn’t possible and you need to prepare stock solutions beforehand, you should aliquot out the solution into tightly sealed vials and store at -20°C. We generally recommend that these will be useable for up to one month. You should also allow the product to equilibrate to RT for at least one hour before opening and using.
Small molecule biochemicals
The majority of our small molecule biochemicals are known to be stable for the duration of shipping and normal handling. As such, they can be shipped at ambient temperature, even if the vial label reads 'store at +4oC or -20oC'. But again – when you receive your biochemical, please make sure you follow the long-term storage instructions on the label or product datasheet.
Some Hello Bio products are known to be temperature sensitive so we ship these on dry ice to maintain their quality during transit. These products are shipped separately from other products on an order and additional shipping/packing charges will apply.
Your product’s appearance
Our typical small molecule biochemical is provided as a powder in a small vial. Some of our products are sold in very small quantities (e.g. 1mg) – these can sometimes be very difficult to see as they may have coated the bottom or the walls of the vial. When you solubilise your product, make sure that the solvent or buffer you are using comes into contact with all areas of the vial. You should vigorously vortex the vial to ensure the product has been completely dissolved.
When you receive our products, you may find it hard to see the product in the vial. Some products which are sold in very small quantities can coat the walls or bottom of the vial or aren’t always visible to the eye. When you using your product, make sure that solvent comes into contact with all areas of the vial.
You may see slight variation in the color and appearance of different batches of the same product, this isn’t a problem and is due to minor differences, crystal shape, water content etc. The quality, purity or biological action of the product will not be affected.
On our product datasheet, you’ll find the CAS number of a product. This is a unique number which is assigned by the Chemical Abstracts Service (CAS) which is part of the American Chemical Society. These unique numbers are given to every chemical which has been described in the literature and helps you to more easily identify a chemical.
Chemical’s are quite tricky however and although we try and give the most accurate CAS number as possible, sometimes you’ll find that the CAS number doesn’t reflect the salt or level of hydration of the product.
On our product pages, we’ve written short overviews of a product’s biological activity and a list of a few suggested references which you may find useful when reading up on a product. The information that we write is intended as a guide, it’s as accurate as possible however it may not be fully comprehensive and may not always be up to date with the most, cutting edge, up-to-date research.
For full details of a product’s biological activity, we recommend that you do some background research of the scientific literature.