Official websites use .gov
A
.gov website belongs to an official
government organization in the United States.
Secure .gov websites use HTTPS
A lock (
) or https:// means you've safely
connected to the .gov website. Share sensitive
information only on official, secure websites.
The effect of (a) pH of phosphate buffer solution, (b) incubation time of antibody and antigen, and (c) HCl concentration. (d) Calibration plot of CEA levels (the inset: UV-vis absorption spectrums in 400 nm–700 nm of colorimetric immunoassay toward different CEA concentrations).
