Both antisera Cat. #16625 and Cat. #17437 are very specific, and are the reagents of choice for the visualization of neurons and peptide secreting neuroendocrine cells by immunocytochemistry. The anti-human NSE can be used for immunocytochemical staining at dilutions of 1:3,000 to 1:5,000. The anti-rat NSE can be used at dilutions of 1:2,000 to 1:4,000. These antisera are also useful for the quantification of neurons and peptide secreting neuroendocrine cells by RIA. The anti-human NSE and anti-rat NSE can be used in conjunction with pure human NSE Cat. #17436 and pure rat NSE Cat. #17435A to formulate an RIA to measure NSE levels in tissue, serum or spinal fluid.