X-ray analysis shows that the nucleated erythrocytes of the amphibian Necturus maculosus (Mud Puppy) contains more ordered chromatin than most nuclei. Here, chromatin fibers were isolated from N. maculosus erythrocyte nuclei using mild micrococcal nuclease digestion, fixed briefly with glutaraldehyde, applied to thin carbon films and negatively stained with aurothioglucose. ~30 nm fibers are seen, some exhibiting short regions with apparent structural order.