150 kDa

While the molecular weight of IgG varies depending on the species, the typical value cited is 150,000 daltons, which is equivalent to 150,000 g/mol. This number comes from IgG's tetrametric structure. IgG contains two heavy chains (50 kDa each) and two light chains (23.5 kDa).

50 + 50 + 23.5 +23.5 = 150