Conjugates covalently linked to our antibodies allow us to visualise binding in our experiments – so choosing the right one to use is a key part of any experimental design.

Today’s data set looks at citations to show which conjugates researchers like best, which they are using most, and which might be less popular.

At the top end of the data set we see HRP (Horse Radish Peroxidase), the traditional conjugate used in Western blotting. HRP has remained the most popular conjugate over the past five years, making up on average around 20 per cent of citations since 2010.

Fluorescent conjugates in action. [Image links to research paper.]
Fluorescent conjugates in action. [Image links to research paper.]

However, not all conjugates have seen such steady use. Dr Andrew Chalmers, founder of CiteAb, said: “Interestingly, from this data set we can see a range of changes in conjugate use over time. Many of these changes are with fluorescent conjugates – an area which has seen plenty of innovation. “We’re seeing greater use of Alexa dyes, and falling use of Cy3, and of older dye FITC – although this still has a large share and is 3rd< overall.”

Take for example the second most used conjugate after HRP – Alexa Fluor 488™, which is now responsible for 13.73 per cent of citations. And among the fastest rising conjugates to be used we have Alexa Fluor 647™, responsible for 1.86 per cent of citations in 2010, increased to 3.67 per cent by 2015. Likewise Alexa Fluor 700™ was another conjugate that has seen significant increase in use over the past five years.

And at the other end of the spectrum, FITC fell from 9.17 per cent of citations in 2010 to 7.98 per cent last year – demonstrating that while this is still among the most used of conjugates it is possibly beginning to go out of fashion. Cy3 fell from 3.97 per cent to 2.33 per cent over the same time period.

Dr Chalmers added: “In addition to a move towards newer dyes we are also seeing more use of IRDye dyes, used for fluorescent western blotting with the LI-COR System, and more use of Dylight dyes, an alternative to fluorescent dyes like the Alexas.”

To see trends in the top ten conjugates or if you want more detailed data on any aspect of conjugate use, (Primary vs Secondary, top antibodies, top suppliers, country use trends) then drop Matt a line and we can discuss available data and pricing with you.

– Katrina and the CiteAb team