Anti-L1CAM antibody [UJ127.11] (ab20148)

Can you tell me if the immunogen is at the N terminal or C terminal?

ANSWER:

Thank you for your enquiry.

I have enquired at the originator of the product but unfortunately, we do not have the immunogen information that you want.

I am sorry I can't be of more assistance in this occasion but should you need any other information, please do not hesitate to contact me.

I have discussed my problems with you and I look forward to your reply.

ANSWER:

Dear Professor Nikiforov,

Thank you for your email and your patience.

I have all of the information that you requested. L1CAM can be detected between 200-220 kD. In brain samples it is typically seen at ~ 200 kD. When the protein is overexpressed in vitro it is often detected as a doublet with bands at 200 and 220 kD. The unglycosylated, unprocessed L1CAM is ~ 140-150 kDa. The protein has 21 putative N-glycosylation sites on the extracellular portion of the protein which, when they are all glycosylated, results in a detected MW of 200-220 kD depending upon how many residues are actually glycosylated. L1CAM can be cleaved by the metalloprotease ADAM10 resulting in fragments of 180 kD and 40 kD. L1CAM can also be cleaved by plasmin resulting in fragments of 140 kD and 80 kD. In theory, therefore, one could detect bands at ~220, 200, 180, 140, 80 and 40 kD.

The most accurate depiction of what you expect to see in Western blotting using an L1CAM antibody is seen on the datasheet for ab24345: a high molecular weight band ~200-220 kD, and two other bands at ~80 and 60 kD. I apologize that our four datasheets have four different molecular weights. I will change these four datasheets so that they all reflect the information I just shared with you. It is possible to see different sizes of the protein based on what samples are being used for detection and whether the protein is glycosylated or cleaved, and this resulted in the confusion of having four datasheets with four different MW’s.

Thank you for sending a picture of your blot. I do not believe that you are seeing the results that you should see with our antibody and I apologize that our datasheet for ab20149 is so poorly written. Both ab20148 and ab20149 are out of stock so I cannot send you a replacement vial of either antibody unless you want to wait several weeks. I suggest that I send you a free of charge replacement vial of ab24345, as this antibody is in stock, has the best datasheet and also has an image of the expected result as well as suggested positive controls (cerebellum, nervous system tissue). Again, I apologize for the several issues that you have had with Abcam and I hope you will let me send this vial of ab24345 to you. I believe you will have good results with ab24345.

I look forward to hearing from you,