IgG2 > IgG3 > IgG4IgAl = circulatory, IgA2 = secretoryMl, M2nonenoneComplimentactivationClassical ++ G4 subclass= alternateAlternate (only IgAl fixes complement)Classical +++AlternateAlternate or NoneSedimentationcoefficient7SMonomer = 7S7S7S8SDimer = 15SPlacental crossingYesNoNoNoNoPresence in milkPresentPresentAbsentAbsentAbsentCompartmentEqual in intravascular (45%) and extravascular(55%)compartmentMostly extravascular (Minimum intravascular distribution)mostlyintravascular MostlyextravascularHeat stabilityStableStableStableStableHeat labileAlso know- Producessecondaryresponse - First to appear in fetus (20 wk)- Producesprimaryresponse Homocytotropic">