Figure 5.

IgG nanobodies as linear secondary detectors in tissue IF. Nanobodies against mouse IgG (A), rabbit IgG (B), or goat IgG (C) were fluorescently labeled with Alexa Fluor 568 (mouse and rabbit) or Alexa Fluor 647 (goat) and used to detect anti-GFP or anti-tdTomato primary antibodies in Thy1-GFPM (A and B) or somatostatin-TdTomato (C) mouse brain sections. Standard monoclonal anti-mouse and polyclonal anti-goat secondaries were also tested. Quantitative comparisons of relative GFP or tdTomato and nanobody/secondary fluorescence are plotted at right. Fluorescence was normalized to maximum fluorescence in each channel. Plots were fitted with simple linear regression, and Pearson correlation coefficients (r) are indicated. The scale bars represent 100 μm. IF, immunofluorescence; IgG, immunoglobulin G.