FAQ – Frequently asked questions

To process your order as fast as possible we need the following specifications:

• Name of institution
• Delivery address
• Invoice address
• VAT/Tax number (for orders from EU)
• Phone number of a contact person for the carrier
• Product code (Catalog number)
• Quantity and package size of each product

Most of our products will be delivered within 2 to 3 days. With your order confirmation you will receive the delivery date.

You can find an overview of our shipping costs on the delivery charges page.

You can pay via

• Wire bank transfer
• PAYPAL
• Credit card

You will find the following documents for the individual products on our homepage: 

• the data sheet with all information on reconstitution, biological activity, stability and area of application
• the certificate of analysis (CoA; batch-related)
• the certificate of origin (CoO)
• the Material Safety Data Sheet (MSDS)

Unless otherwise stated on the product data sheet, all our products are formulated so that the lyophilized proteins are very stable at room temperature. Nevertheless, we recommend storage at -20 °C to -80 °C. 

For reconstituted solutions of most proteins, we recommend short-term storage at 4 °C. For longer periods of time, the protein solution should be mixed with a carrier protein (e.g. 0.1 % BSA), aliquoted and stored at -20 °C to -80 °C. The concentration of the aliquots should not be less than 1 µg/mL and the volume should be at least 10 µL (regardless of the concentration).

We recommend not to subject the aliquots to more than one freeze/thaw cycle, as each freeze/thaw cycle can cause denaturation of the protein.

The endotoxin content is guaranteed to be below 0.1 ng/µg or 1 EU/µg. The measured endotoxin values are usually well below this limit.

We use the LAL method (kinetic-turbidimetric method) for endotoxin determination in accordance with Ph.Eur.  2.6.14. (11.6).

Most products are formulated without carrier proteins or additives. Therefore, the proteins can be deposited as a partially invisible film during lyophilization in small container sizes.

Before opening, we recommend centrifuging the vial for 30 seconds so that the entire amount of protein collects at the bottom of the vial. 

Our quality control procedures ensure that the correct quantity has been filled in each case.

With a few exceptions, most human cytokines are also active on mouse cells. Many mouse cytokines are active on human cells, but with a lower specific activity.

Some human cytokines, such as intereferons, GM-CSF, IL-3 or IL-4, are species-specific and show little or no activity on non-homologous cells.

FGFs and neurotrophins are highly conserved and show very good activity on cells of other species.

While the ED50 is defined as the cytokine concentration at which the activity is 50% of the maximum response, the specific activity is defined as the measurement of the reaction rate (i.e. activity) in relation to the amount or mass of a substance. Units of specific activity should only be used as a method to indicate potency and should only be calculated for sigmoidal dose-response curves. 

From the ED50 value, the following formula is used to obtain the specific activity in units/mg:

1000000/ED50 (ng/mL) = specific activity (Units/mg)