2.5. Immunofluorescence
Kidneys were isolated from CRIg-Fc and control treated mice and immediately frozen into Tissue-Tek OCT compound. Sections (5 μm thickness) were cut on a cryostat, fixed in acetone and washed successively in 1× PBS (Phosphate Buffered Saline) three times and blocked with 10% BSA in PBS for 30 min. Diluted FITC-anti-mouse IgG (Jackson Immunoresearch, West Grove, PA) or anti-mouse C3 (Hycult Biotech, Plymouth Meeting, PA) antibodies were incubated overnight at 4 °C, and goat anti-mouse FITC antibody was used as a secondary antibody for C3. Sections were visualized with a Nikon C1 confocal microscope. The fluorescence intensity of glomeruli from each animal was calculated using Image J software. At least 20 glomeruli per section were analyzed and scored.
2.6. Statistical analysis
Two-tailed Students t test were used for data analysis and p values of ≤0.05 were regarded as statistically significant.