Immunolocalisation of insulin and IGF2 protein in the tammar mammary gland. Insulin (A), (C) and (E) and insulin-like growth factor 2 (IGF2)(B), (D) and (F) protein (brown staining) localisation in mammary glands at three different stages of lactation. (A), (B) One day before birth (day −1), macrophage cells (M) in the stroma (S) were intensely stained and there was no staining in the alveolar cells (Av). (C), (D) At day 95 of lactation, insulin and IGF2 was detected in the cytoplasm of the alveoli epithelial cells (Ep), with infrequent macrophage cell staining. (E), (F) At day 200 of lactation, staining was concentrated in the epithelial cells of the alveoli. There was no staining in any of the IgG antibody control (top right insert). There was no staining in any of the no-antibody controls (data not shown). Scale bars shown at the bottom right.