I am planning to do experiments with nude (Hairless SCID) mice (weight is 22-27 g). The tested substance will be administered orally using feeding tube. Maybe somebody could advice which size of feeding tube could be the best choice for such mice? We used plastic feeding tube, 18 ga (1.2 mm) x 38 mm for Balb/c mice (15-18 g) in the previous experiments, but did not perform such experiments for SCID mice before.