Highly Sensitive Immunochromatographic Identification of Tetracycline Antibiotics in Milk

Table 2

The dependence of TC immunochromatographic assay on IgG-GNP conjugate concentration.

OD520 of the conjugate	Limit of TC detection, ng/mL	Maximal coloration, RU	Background coloration, RU
2	0.16 ± 0.06	11,100 ± 568	270 ± 58
4	0.1 ± 0.02	11,600 ± 251	170 ± 25
8	1.8 ± 0.18	12,000 ± 485	5,000 ± 186