Table 4

Shelf life of ELISA assay at 4°C and -20°C

4°C

-20°C

Positive Control

(mean+SD)

Negative Control

(mean+SD)

Positive Control

(mean+SD)

Negative Control

(mean+SD)

One Month

0.962 ± 0.037

0.168 ± 0.009

0.898 ± 0.058

0.155 ± 0.061

Two Months

0.934 ± 0.041

0.155 ± 0.014

0.845 ± 0.025

0.147 ± 0.039

Three Months

0.878 ± 0.014

0.145 ± 0.023

0.797 ± 0.006

0.115 ± 0.011

Four Months

0.863 ± 0.023

0.127 ± 0.008

0.752 ± 0.009

0.104 ± 0.008

Five Months

0.856 ± 0.005

0.139 ± 0.012

0.793 ± 0.052

0.113 ± 0.043

Six Months

0.832 ± 0.034

0.143 ± 0.051

0.721 ± 0.048

0.133 ± 0.029

Mei et al. Virology Journal 2012 9:4   doi:10.1186/1743-422X-9-4