Bca protein concentration determination assay kit

According to the manufacturer’s instructions, proteins were extracted from cells or tissues using Western-IP Lysis Buffer (Beyotime, Shanghai, China). The protein concentration was determined using a bicinchoninic acid (BCA) protein concentration determination assay kit (Beyotime, Shanghai, China). Prepared samples were electrophoresed in a 10% SDS-PAGE gel and blotted onto a polyvinylidene fluoride (PVDF) membrane (Millipore, USA) using the Tetra Handcast system (Bio-Rad, USA). The membranes were blocked for 3 h at room temperature and incubated overnight at 4°C with an appropriate primary antibody in Tris-buffered saline with 0.05% Tween (TBST) containing 5% non-fat milk. After washing in TBST, the membranes were incubated with secondary antibody, washed and visualized using a supersensitive enhanced chemiluminescence (ECL) kit (Beyotime Institute of Biotechnology, China) according to the manufacturer’s protocol. The protein bands were detected and quantified using the Gene Gnome Syngene Bio Imaging System (SYNGENE, UK).
Primary antibodies used for Western blotting included a mouse monoclonal anti-SK4 antibody (1:100; Alomone Labs, Israel), a rabbit polyclonal ER antibody (1:1,000; a gift from Dr. Yibing Hu), a rabbit monoclonal anti-EMT antibody sampler kit (1:1,000; Cell Signaling Technology, USA) and a mouse monoclonal anti-tubulin antibody (1:500; abcam, USA).

The spinal cord tissues (L3-L4) were homogenized in a lysis buffer containing Protease Inhibitor Cocktail (p8340, Sigma-Aldrich) [19 (link)]. The protein concentration was confirmed with BCA protein concentration determination assay kit (P0010, Beyotime, Shanghai, China). The protein samples were separated by SDS-PAGE gels and transferred onto polyvinylidene fluoride membrane (IPVH00010, Millipore). The membrane was sealed with 5% skim milk for 2 h at room temperature, subsequently incubated at 4°C overnight with the primary antibodies: Mtf1 (1 : 500; Santa Cruz Biotechnology, CA, USA), p-ERK1/2 (1 : 5000; Sigma), ERK1/2 (1 : 1000; Santa Cruz Biotechnology), GFAP (1 : 1000; Cell Signaling Technology, Danvers, MA, USA) and β-actin (1 : 2000; Santa Cruz Biotechnology). The membrane was washed for 5 min/time 3 times at room temperature, incubated for 2 h in the corresponding secondary antibody: HRP-labeled goat anti-mouse IgG (1 : 1000; Beyotime), HRP-labeled goat anti-rabbit IgG (1 : 1000; Beyotime) and HRP-labeled donkey anti-goat IgG (1 : 1000; Beyotime) at room temperature. The membrane was then washed for 5 min/time 6 times, the immune complexes were detected by ECL chemiluminescent assay kit (Biosharp, Guangzhou, China). Signal intensity of band analyses was conducted with ImageJ software (Alliance Q9).