Sheep anti-glucagon Ab (Abcam) did not work at all. Other glucagon Abs except mouse monoclonal (Sigma) seem very questionable in terms of quality. Like,for Goat anti-glucagon (Santa Cruz), the fluorescent bleaches away within a minute. I am also looking for a good glucagon Ab. But to answer your question, I would suggest to stick to mouse anti-glucagon Ab (Sigma). Make your experimental plan in such a way that you should use mouse anti-glucagon Ab. That's all I can suggest. Good Luck.