Biotin Labeling Kit-NH2 is mainly used for the preparation of biotin-labeled IgG for enzyme immunoassay (EIA). This kit contains all the reagents necessary for the labeling. The labeling process is very simple. Just add the NH2- reactive Biotin to IgG solution and incubate at 37oC for 10 minutes. An average of 5 to 8 biotin molecules conjugate to each IgG molecule. The number of biotin molecules per protein can be determined by HABA assay. Excess biotin molecules can be removed by a filtration tube.