Selecting reagents for a lateral flow device (LFD) is a key stage in the development of an LFD, and the selection process involves several key considerations. In this article, we highlight those key considerations. Although we mainly discuss antibodies, the following also applies to the selection of all reagents, whether it is an antibody, antigen or aptamer etc.

Key considerations for selecting LFD reagents

When a client who already has access to reagents approaches us to commence an assay development project we establish the following. We do this for a number of reasons, but mainly to ensure the reagents are going to the most suitable for the duration of the assay's time in the market. We also determine the following when selecting reagents for our internal products or when sourcing reagents for our clients who don't currently have access to reagents.

So what do we look for and what pointers can we give people looking to source and select lateral flow device reagents?

Original manufacturer - Once an antibody has been identified on a supplier’s website you need to establish if they are the original producer of the clone. Ask if they hold the cell line. Check that there are no restrictions on the sale or usage of the antibody, many companies do not allow their antibodies to be used for commercial use.

Guaranteed supply – many antibodies can be purchased in small volumes, up to a couple of milligrams, which is fine for the development of the assay but what happens if you need 10mg for a pilot batch, or 50mg for a manufacturing batch? Asking this question will often give an indication of the availability of the cell line if they can’t supply in bulk they are unlikely to hold it.

Cost – An antibody can typically cost £500 - £1000 per mg, which is fine for a couple of milligrams for assay development but if you are paying the same price for 50mg this will have a significant impact on the final device cost. Again if a significant reduction in cost is not available for bulk its unlikely they hold the cell line.

Once it’s been established the antibodies are working well in the assay the supply needs to be secured.

Exclusivity - Would the supplier consider an exclusive supply agreement for a minimum purchase? They may have only sold a few milligrams previously and would be willing to offer exclusivity of supply for a guaranteed purchase per annum. If the test is unique, securing an exclusive antibody supply will prevent another party from developing a similar assay using the same antibody. Some companies may ask for a royalty on sales in return.

If exclusivity cannot be obtained, a supply agreement is essential to ensure a continuous supply of reagent. A large investment will have been made in the development project to get the assay to the manufacturing stage, it is crucial to secure the supply of all components.

Suitability - This is obvious, but like mentioned earlier, the reagents need to work, which of course will be established during feasibility and optimisation of a test.

Where to source reagents?

Some clients approach us wanting to develop an LFD already having access to reagents but some of our customers do not. So as part of Abingdon Health’s contract lateral flow assay development program, we can offer:

Reagents sourcing and selection

Abingdon Health will carry out a full search of commercially available reagents for the assay to be developed, following all the above steps to ensure we secure suitable reagents for your project. We have a number of suppliers we work in partnership with to ensure we get the most suitable reagents at the best price.

Antibody and antigen generation

If suitable commercially available reagents are not available, or if a client would prefer the security of having their own reagents, we have a number of suppliers we work closely with to generate antibodies and antigens, some of which can be available in as little as 10 weeks.

Growth and maintenance of cell lines

We work with partners who can provide bulk production of your cell lines quickly and efficiently, ranging from a few milligrams up to multiple gram quantities. They can also provide purification services and secure cell banking.

Need help with reagent sourcing?

If you would like assistance in sourcing reagents for lateral flow assays please feel free to contact us on +44 (0) 1904 406050 or [email protected].

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