Abstract: In order to get high quality gold-monoclonal antibody of progesterone, the colloidal gold particles of 30 nm was prepared by the tri-sodium citrate reduction method, and then identified by two different ways. The key experiment conditions to develop gold-monoclonal antibody of progesterone were optimized. The spheroidal colloid gold particles of 30 nm was shown in color of bright red, and the equal particle ultrastructure was observed through transmission electron microscope(TEM); the minimal stable concentration (MSC) of gold-monoclonal antibody was 16 μg/mL, and the suitable stable concentration (SSC) was 19.2 μg/mL. The pH 8.5 was appropriate. Obvious low electron density halo was obversed around the particle of gold-monoclonal antibody complex, and the D_{520 nm} was in the range of 0.2 to 0.4, thereby preparing for further research on the gold immunochromatography test strip of rapid diagnosis of pregnancy.

Key words: colloid gold; monoclonal antibody of progesterone; gold-monoclonal antibody