Ig vs immune serum globulin

Ig and immune serum globulin both are nouns.

Word	Noun	Adjective	Verb	Adverb
Ig	Yes	No	No	No
immune serum globulin	Yes	No	No	No

As nouns, Ig and immune serum globulin are synonyms defined as:

Ig and immune serum globulin: a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response

Other synonyms of Ig include immune gamma globulin, immune globulin, immunoglobulin.

Ig (noun)	immune serum globulin (noun)
a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response	a class of proteins produced in lymph tissue in vertebrates and that function as antibodies in the immune response