Demonstration of CENP-E messenger RNA and protein in rheumatoid synovium by in situ hybridization and immunohistochemistry. (a, b) A digoxigenin-labelled RNA probe transcribed from the amplified RNA arbitrarily primed-PCR gene product is used on rheumatoid arthritis snap-frozen sections. Double-labelling for CENP-E messenger RNA (black staining), and alkaline phosphatase antialkaline phosphatase counterstaining using anti-fibroblast antibodies (red staining) shows CENP-E expression in numerous fibroblasts througout the synovium (a, arrows). (b) The intensive CENP-E messenger RNA expression in two synovial fibroblasts. (c) Shows numerous fibroblasts expressing CENP-E protein [black staining (arrows), counterstaining with fast red]. Original magnifications × 300 (a, c) and × 600 (b).