The datasheet normally includes the applications that have been already tested and for which the antibody can be recommended. That does not necessarily exclude that other applications can be possible, you would have to try.

But a very important thing to have in mind is that some antibodies can indeed recognize the antigen in a given experimental format and not in others. It depends on the unique combination of epitope specificity and affinity each antibody has. For instance

a. an antibody that recognizes a conformation sensitive epitope that depends on the proper 3D folding of the antigen could be useful to recognize the native antigen in ELISA or flow cytometry, but is likely not reactive (or less reactive) with denatured linear antigen in western blot.

b. an antibody that recognizes an epitope that can be destroyed by solvents and chemicals used to treat tissue in IHC can be useful for other applications, but not for IHC.

c. an antibody that recognizes a linear epitope in the intracellular domain of a membrane antigen can recognize the antigen in western blot, but not in flow cytometry, because the epitope is hiden, unless the cells are permeabilized before staining.

d. an antibody that recognizes an epitope located in the interface of a given antigen with an interacting partner on the cell membrane can be used to bind the purified antigen, but would be unable to detect the antigen in its natural form (a supramolecular complex) on cells.

There are many more examples. Each antibody can have multiple applications or its usefulness can be restricted to one or a few kinds of experiments.

The antibody may be the same, but the state of the antigen is not- for flow cytometry, you will normally need an antibody recognizing the folded extracellular domain of a cell surface protein. In Immunehistochemistry, you are frequently dealing with fixed cells, therefore your antigen may or may not be denatured. In western blotting, the antigen definitely is denatured, therefore you need an antibody that recognizes the unfolded protein.

The datasheet normally includes the applications that have been already tested and for which the antibody can be recommended. That does not necessarily exclude that other applications can be possible, you would have to try.

But a very important thing to have in mind is that some antibodies can indeed recognize the antigen in a given experimental format and not in others. It depends on the unique combination of epitope specificity and affinity each antibody has. For instance

a. an antibody that recognizes a conformation sensitive epitope that depends on the proper 3D folding of the antigen could be useful to recognize the native antigen in ELISA or flow cytometry, but is likely not reactive (or less reactive) with denatured linear antigen in western blot.

b. an antibody that recognizes an epitope that can be destroyed by solvents and chemicals used to treat tissue in IHC can be useful for other applications, but not for IHC.

c. an antibody that recognizes a linear epitope in the intracellular domain of a membrane antigen can recognize the antigen in western blot, but not in flow cytometry, because the epitope is hiden, unless the cells are permeabilized before staining.

d. an antibody that recognizes an epitope located in the interface of a given antigen with an interacting partner on the cell membrane can be used to bind the purified antigen, but would be unable to detect the antigen in its natural form (a supramolecular complex) on cells.

There are many more examples. Each antibody can have multiple applications or its usefulness can be restricted to one or a few kinds of experiments.

Nice answer Gertrudis!!

Are you sure the antibody is actually the same? The hybridoma producing the anti-CD3 sold by Thermofisher is not necessarily the same producing the anti-CD3 sold by AbCam.

Alejandro is right. I assumed that the target is the same, but the antibodies are different (each produced by a particular hybridoma clone and recognizing a given epitope). Do you think both companies sell exactly the same molecule? Why?

If both companies provide exactly the same molecule, I would think that each company recommends the applications they have already tested.

Annemarie Honegger Gertrudis Rojas Alejandro Martin

thank you all for your answers!

The examples I mentioned were not actual products. I just made that up for asking...

Now I understand that if the same antibodies are made from different hybridoma clone, they each have slightly different characteristics?

Different hybridoma clones, often even derived from different immunizations, will give you different antibodies against the same antigen: The sequences of the antibodies will be different, may be derived from different germlines, and may recognize different epitopes in the antigen.

Seonggyu Kwon, if they come from different hybridomas they are not the "same" antibody, and may be so different that "slightly" becomes an understatement. Suppose, for instance, that you have two hybridomas against the same viral envelope antigen, one producing an antibody that binds a linear peptide buried deep into the hydrophobic core of the protein (obtained, let's say, by immunization with a KLH-peptide conjugate), and the other, binding a solvent-accessible quaternary epitope spanning the interface between several adjacent protein monomers on the viral surface. They both recognize the same antigen, but their properties will be vastly different (the first will be good for not much more than Western blotting; the second will bind nothing in Western blots but will be great at virus neutralization, etc).

Hope it helps!