Aluminum nodules have features consistent with ETs. (A) Alhydrogel nodules (10 μg, 3 μg) were analyzed by Western blot for the presence of histone H3, compared with spleen cells (1.0, 0.3, 0.1, 0.03 × 106 cell equivalents). (B) Alhydrogel nodules were digested in the presence of DNase alone, proteinase K alone, or both. Absorbance of released material was measured at 280 nm. (C) Aluminum nodules were analyzed by Wright-Giemsa staining at ×1000 magnification. N indicates neutrophil; E, eosinophil; M, mononuclear cell. (D) Aluminum nodules were analyzed by immunofluorescence staining for DNA with DAPI (blue) and myeloperoxidase (red). (E) A gel identical to that shown in panel A (and run in parallel) was analyzed by Western blot for the presence of citH3. All experiments used Alhydrogel nodules collected 4-5 hours after injection and were performed at least 3 times.
