ster and derivatives thereof, N-succinimidyl(4-iodoacetyl)aminobenzoate (SIAB) and derivatives thereof including N-succinimidyl(4-iodoacetyl)aminobenzoate (Sulfo-SIAB), maleimido butryloxy-succinimide ester (GMBS) and derivatives thereof including, but not limited to, m-MaleimidoButyryloxy-SulfoSuccinimide ester (Sulfo-GMBS), N-(e-MaleimidoCaproyloxy)-N-HydroxySuccinimide ester (EMCS) and derivati