To block nonspecific sites and permeabilize cells. The samples were incubated with primary antibody overnight at 4uC. After washing in 0.1 mol/L PBS 3 times, the samples were incubated by second antibody for 60 minutes in dark at 37uC. After washing 3 times in 0.1 mol/L PBS, the cells were coverslipped immediately with Vectashield anti-fade mounting media (Santa Cruz Biotechnology, USA) and stored at 4uC until observation by fluorescent microscope. Primary antibody: mouse monoclonal anti-MAP-2 (1:400, abcam, Hong Kong); rabbit polyclonal anti-NF200 (1:500, abcam, Hong Kong); rabbit monoclonal anti-GAP-43 (1:1,000, abcam, Hong Kong); rabbit polyclonal anti-muscle actin (1:500, Abcam, Hong Kong). Second antibody: goat anti-mouse conjugated to Cy2 (1:400, abcam, Cambridge, UK); goat anti-rabbit conjugated to Cy3 (1:400, abcam, Cambridge, UK).Western blot assay of NF-200 and GAP-43 proteinThe protein levels of NF-200 and GAP-43 in DRG in neuromuscular coculture and DRG culture alone at 6 days of culture age were analyzed by Western blot assay, with b-actin as an internal control. The DRG explants were DprE1-IN-2 removed from 24well clusters on ice and homogenized in 10 mmol/L Tris homogenization buffer (pH 7.4) with protease inhibitors (Sigma, USA). The samples were centrifuged at 10,000 g for 20 minutes at 4uC. After determining the protein concentrations of the supernatants (BCA method, standard: BSA), about 50 mg protein per lane were resolved by SDS-PAGE (10 ), and telectrotransferred to nitrocellulose membranes followed by blocking with 5 dry milk K162 cost powder for 1 h and immunostaining with the respective primary antibody dilution for 1 to 4 h at RT or over night at 4uC. The membranes were incubated with primary antibodies: rabbit anti-NF-200 polyclonal IgG (1:1,000, abcam, Hong Kong); rabbit anti-GAP-43 monoclonal IgG (1:100,000, abcam, Hong Kong); or mouse 23727046 anti-b-actin monoclonal IgG (1:4,000, Santa Cruz Biotechnology, USA). After being washed three times for 10 minutes with washing solution, the membranes were incubated with second antibody: goat anti-rabbit IgG-HRP (1:5,000, Santa Cruz Biotechnology, USA) or goat anti-mouse IgG-HRP (1:4,000, Santa Cruz Biotechnology, USA). Peroxidase activity was visualized with the ECL Western blotting detection kit 24195657 (Millipore, Billerica, USA) according to the manufacturer’s instructions, and protein content was determined by densitometrically scanning the exposed x-ray film and the images were analyzed quantitatively by using an ImageJ 1.39u image analysis software. The levels of NF200 and GAP-43 were expressed as the ratio of the protein to bactin.Determination of total migrating neurons and the percentage of NF-200-IR or GAP-43-IR neurons from DRG explantsTotal migrating neurons from DRG explants were determined as MAP-2-immunoreactive (IR) neurons under a fluorescence microscopy (Olympus) with 206 objective lens. MAP-2-IR neurons in one visual field at the edge of DRG explants were counted as the total migrating neurons in each sample. The migrating NF-200-IR or GAP-43-IR neurons from DRG explants were observed under a fluorescence microscope (Olympus) with 206 objective lens. NF-200-IR or GAP-43-IR neurons in one visual field at the edge of DRG explants were counted asTarget SKM on Neuronal Migration from DRGStatistical analysisData are expressed as mean 6 SEM. All the data were processed for verifying normality test for Variable. The normality tests have passed for all the data. Statistical analysis was ev.To block nonspecific sites and permeabilize cells. The samples were incubated with primary antibody overnight at 4uC. After washing in 0.1 mol/L PBS 3 times, the samples were incubated by second antibody for 60 minutes in dark at 37uC. After washing 3 times in 0.1 mol/L PBS, the cells were coverslipped immediately with Vectashield anti-fade mounting media (Santa Cruz Biotechnology, USA) and stored at 4uC until observation by fluorescent microscope. Primary antibody: mouse monoclonal anti-MAP-2 (1:400, abcam, Hong Kong); rabbit polyclonal anti-NF200 (1:500, abcam, Hong Kong); rabbit monoclonal anti-GAP-43 (1:1,000, abcam, Hong Kong); rabbit polyclonal anti-muscle actin (1:500, Abcam, Hong Kong). Second antibody: goat anti-mouse conjugated to Cy2 (1:400, abcam, Cambridge, UK); goat anti-rabbit conjugated to Cy3 (1:400, abcam, Cambridge, UK).Western blot assay of NF-200 and GAP-43 proteinThe protein levels of NF-200 and GAP-43 in DRG in neuromuscular coculture and DRG culture alone at 6 days of culture age were analyzed by Western blot assay, with b-actin as an internal control. The DRG explants were removed from 24well clusters on ice and homogenized in 10 mmol/L Tris homogenization buffer (pH 7.4) with protease inhibitors (Sigma, USA). The samples were centrifuged at 10,000 g for 20 minutes at 4uC. After determining the protein concentrations of the supernatants (BCA method, standard: BSA), about 50 mg protein per lane were resolved by SDS-PAGE (10 ), and telectrotransferred to nitrocellulose membranes followed by blocking with 5 dry milk powder for 1 h and immunostaining with the respective primary antibody dilution for 1 to 4 h at RT or over night at 4uC. The membranes were incubated with primary antibodies: rabbit anti-NF-200 polyclonal IgG (1:1,000, abcam, Hong Kong); rabbit anti-GAP-43 monoclonal IgG (1:100,000, abcam, Hong Kong); or mouse 23727046 anti-b-actin monoclonal IgG (1:4,000, Santa Cruz Biotechnology, USA). After being washed three times for 10 minutes with washing solution, the membranes were incubated with second antibody: goat anti-rabbit IgG-HRP (1:5,000, Santa Cruz Biotechnology, USA) or goat anti-mouse IgG-HRP (1:4,000, Santa Cruz Biotechnology, USA). Peroxidase activity was visualized with the ECL Western blotting detection kit 24195657 (Millipore, Billerica, USA) according to the manufacturer’s instructions, and protein content was determined by densitometrically scanning the exposed x-ray film and the images were analyzed quantitatively by using an ImageJ 1.39u image analysis software. The levels of NF200 and GAP-43 were expressed as the ratio of the protein to bactin.Determination of total migrating neurons and the percentage of NF-200-IR or GAP-43-IR neurons from DRG explantsTotal migrating neurons from DRG explants were determined as MAP-2-immunoreactive (IR) neurons under a fluorescence microscopy (Olympus) with 206 objective lens. MAP-2-IR neurons in one visual field at the edge of DRG explants were counted as the total migrating neurons in each sample. The migrating NF-200-IR or GAP-43-IR neurons from DRG explants were observed under a fluorescence microscope (Olympus) with 206 objective lens. NF-200-IR or GAP-43-IR neurons in one visual field at the edge of DRG explants were counted asTarget SKM on Neuronal Migration from DRGStatistical analysisData are expressed as mean 6 SEM. All the data were processed for verifying normality test for Variable. The normality tests have passed for all the data. Statistical analysis was ev.