From batch-to-batch variability and cross-reactivity to unclear antibody supply lines and incorrect datasheets supplied by manufacturers, the commercial antibody industry is a mess. An article published in this week’s edition of Nature (link is external) reminds us of the many reasons that antibody use within life science research is so fraught with error. Unfortunately being unable to rely on key research tools leaches its effects into the world of protein research, with research articles being retracted (link is external) and much of the published data unreproducible (link is external).
David Rimm (link is external), now one of the chief champions of antibody validation, spent three years from 2006-2009 developing a test to inform melanoma treatment. All of this work had to be scrapped when a new batch of antibodies, supposedly identical to those upon which they had developed the test, showed variability, negating all the work that had gone before.
The tales of researchers hunting through off-the-shelf antibodies for just one that is ‘specific enough’ and works in their desired applications abound. Studies show that swathes of antibodies in the fields of G-protein coupled receptors (link is external) and epigenetics (link is external) exhibit a lack of target specificity, and failing antibody specificity is by no means limited to these fields, with work from the Human Protein Atlas project suggesting that up to 50% of antibodies are unreliable (link is external).
Dr Ioannis Prassas (link is external), a postdoc at Mount Sinai worked for two years on a project developing pancreatic cancer tests and spent over $500, 000 before discovering that the antibody they were using to track the CUZD1 protein bound to a different protein and did not bind to CUZD1 at all. In retrospect he admits he should have properly validated the antibody before use. But, attempting to validate an antibody at the beginning of a project does not necessarily discount problems as David Rimm’s story shows. Dr Simon Glerup (link is external) from Aarhus University spent three months and large sums of money searching through commercial antibodies to the receptor tyrosine kinase TrkB, where 90% of the antibodies failed to work in the way promised by suppliers.
It is estimated that of the over 2 million antibodies commercially available from more than 300 antibody vendors that only between 12-25% of these are actually unique antibodies (link is external). The rest represent antibody suppliers buying up each other’s catalogues and relabelling the products as their own. With the same antibodies sold as different products through the different companies buyers must beware that when searching through the hoards for an antibody that is specific and performs in the desired application, that they do in fact trial different antibodies and not just differently labelled pots of the same antibody.
To circumvent this problem many rely on previously published data to identify antibodies to their targets. This leads inevitably to a situation of survival of the first antibody to a target rather than survival of the best. To identify newer, better antibodies would require comparative tests of all antibodies to a target; investigations that would require both time and money, things which are in short supply in the data-driven research world.
The research community is increasingly acknowledging the problems with antibody use. However, the recent petition to Nature signed by over 100 scientists, which called for all antibodies to be catalogued by their sequence and for production in animals to cease, is recognised to be over-ambitious. Whilst this approach may standardise antibodies across the research community some think it may not solve the problem of validation of these research tools. Professor Mathias Uhlén, of the Human Protein Atlas project, believes that beyond increasing antibody costs by 10-100 times a guaranteed antibody sequence would not guarantee improved performance or that the antibody would work in a scientist’s desired application.
Despite a developing awareness amongst researchers of the failures of antibodies and a call from journals for increased validation of antibody-dependent experiments with manuscript submissions, improvements in antibody products themselves are slow to materialise. Validation websites such, as CiteAb (link is external), Antibody Registry (link is external), Antibodypedia (link is external) and pAbmAbs (link is external), have arisen to try and help researchers navigate the tricky landscape of functional antibodies, offering researchers own reviews of individual antibody function in different applications. Yet many scientists are unaware of these resources and if the antibodies that you are interested in have received only negative reviews or no reviews, where then?
Thankfully there is now another option available to researchers. Affimer technology has been developed by Avacta Life Science to address the previously unmet research need for highly specific affinity reagents that don’t suffer from batch-to-batch variability problems. Only Avacta Life Science sell Affimer reagents so you know that what we say you are buying is what you will be supplied with and will work as we state on the product sheet and as our custom service (link is external) only take 7 weeks to develop and validate they won’t stall your project.
For more information, contact us (link is external).