Dimethylbenzene

The silkworm strain used in the experiment was Bombyx mori (871 × 872), sourced from the Chongqing Sericulture Science and Technology Research Institute (Chongqing, China). Ammonium molybdate tetrahydrate (AMT) was purchased from Shanghai Darui Fine Chemical Co., Ltd. (Shanghai, China); sodium chloride was purchased from Shanghai Aladdin Bio-Chem Technology Co., Ltd. (Shanghai, China); nitric and perchloric acids were purchased from Beijing Institute of Chemical Reagents (Beijing, China); sodium carbonate and ethanol were purchased from Chongqing Chuandong Chemical Co., Ltd. (Chongqing, China); potassium bromide was purchased from Sangon Biotech Co., Ltd. (Shanghai, China); hematoxylin and eosin (H&E) staining kits were purchased from Nanchang Yulu Experimental Equipment Co., Ltd. (Nanchang, China); dimethylbenzene and poly (tetrafluoroethylene) were purchased from Shanghai Macklin Biochemical Co., Ltd. (Shanghai, China); Super P was purchased from Canrd New Energy Technology Co., Ltd. (Guangzhou, China); and foam Ni was purchased from Taiyuan Lizhiyuan Co., Ltd. (Shanxi, China). All chemicals were of analytical grade and used without further purification. The deionized (DI) water used in this work was produced using a Milli-Q Direct-8 purification system (resistivity >18 MΩ cm, Millipore Inc., France) onsite.

Human tissues were fixed in 10% formalin (Solarbio, Beijing, China) and embedded in paraffin. Five-micrometer sections were dewaxed with dimethylbenzene (Macklin, Shanghai, China) and dehydrated in a gradient ethanol series, followed by incubation with citrate buffer for antigen recovery. Hydrogen peroxide (Macklin, 3%) was used to block the endogenous peroxidase activity. The sections were incubated with primary antibodies against KIF21B (1:500; Thermo Fisher) overnight at 4°C. The sections were then stained using biotinylated secondary antibodies at 37°C for 20 min and exposed using DAB. The images were captured by microscopy (Leica, Wetzlar, Hesse-Darmstadt, Germany). Three fields were randomly selected, and the average percentage of brown or dark yellow particles in the cytoplasm was counted.