Prox1 antibody woes

Antibodies are funny. Funny in that sometimes they work and sometimes they don’t, sometimes they have different names at different vendors, and sometimes papers do, and sometimes they don’t, specify the catalog number of the antibody they used. So a bit of detective work is required if you want to avoid wasting a few hundred dollars on a new antibody. Here is yesterday’s detective story.

Prox1 seems to be the best marker of dentate gyrus granule neurons. It is expressed very early in development and in both immature and mature cells in the adult brain. So if you want to ID a granule neuron, Prox1 is your man/woman. From my research, Millipore’s AB5475 seems to give good staining and is very commonly-used. On their website you can see a picture of representative staining with their antibody:

MILLIPORE 

But after backorder notification upon backorder notification we got impatient and decided to look elsewhere. Looking for other rabbit-based Prox1 antibodies we came across:

COVANCE.

The Covance antibody (PRB-238C) has been used in several good papers, and the immunostaining picture is the same as the Millipore picture. Both are directed against the C-terminus of Prox1 so I assumed they’re the same antibody. But Covance said their antibody is not the same and that they make theirs in house. Anyway, it’s on backorder too. So…

ABCAM.

Now I just can’t help but notice that Abcam’s 37128 antibody has the same immunostaining pictures as Millipore and Covance. But their antibody would appear to be completely different, as it is directed against the N-terminus of Prox1.

So what the heck is going on?

Anyway, we’re going with goat. (Prox1 antibody (AF2727) from R&D Systems)

Post-Twitter Convo UPDATE: The Journal of Comparative Neurology Antibody Database and the Antibody Registry may prove helpful in some cases.