To establish an efficient assay method for detecting nitric oxide indirectly, we compared the effects of cadmium filing, 5mmol/L and 80mmol/L copperized cadmium filing on the measurement of nitrates and nitrites (the stable products of NO) using the cadmium reduction method. The results demonstrated that cadmium filing was the most efficient cadmium preparations ( P <0.001). It's mean reduction rate was 96%, and it showed stronger reduction effectiveness in deproteinization cell culture media. The res...