This kit used the double antibody sandwich method to determine the level of vitamin K1 (VK1) in fish (Shanghai Hengyuan Biological Technology Co., Ltd., H-42702, Shanghai, China). The monoclonal antibody vitamin K1 was added into the micropore and combined with horseradish peroxidase (HRP) to form a complex. After polyester, tetramethylbenzidine (TMB) was added to develop color. Under TMB catalysis, it was transformed to blue. There was a positive correlation between the color and the fish vitamin K1 in the fish, measured at 450 nm by enzyme-linked immunosorbent assay. The absorbance (OD value) of fish vitamin K1 in the sample was calculated by the standard curve. To determine the cMGP levels, a human matrix gamma carboxyglutamic acid protein (cMGP) detection kit was selected (Shanghai Hengyuan Biological Technology Co., Ltd., H-11621, Shanghai, China). The purified HRP labeled cMGP antibody was coated on the microporous plate to form a complex. After thorough washing, the substrate TMB was added for color rendering. The experiment was repeated three times.