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Difference between immunoglobulin and antibody? - (Mar/06/2013 )

What is the difference between immunoglobulin and antibody?


But why there are two words? There must be some difference.


There are many different types of immunoglobulin, these are referred to as Ig followed by a letter, for instance IgG or IgA and refers to all immunoglobulins of that type. An antibody is raised against a specific antigen and will be a specific form of one of the immunoglobulins.


Hi Bob, you are so versatile.

Can i say that IgG can be used to fight all bacterial or viral infection? And I see from a website that antibody is one of those IgA/M/G/D/E.
The website is


Yes, IgG is used to fight infections, but I'm no immunologist, so I don't really know much more than that. I do also know that IgM has something to do with infection, as its titre rises early in infection and then goes away. I am sure Wikipedia has a good basic explanation of all of them.


Agree with Bob and clinically speaking, if the IgM titre of a certain antibody is high, you can infer that the person has got a relatively fresh infection, still in its early phase, while a high IgG titre shows you that the person is either having that infection currently but not quite fresh - or had it once, built antibodies against it and is immune now.


the different immunoglobulin classes are structurally different, and play different (but overlapping) roles. I would definitely check out Wiki; they seem to treat antibodies pretty well in general and it will explain the differences to you.