Concentrations of orexin-A in cerebrospinal fluid are markedly decreased in patients with narcolepsy, a sleep disorder. This suggests a crucial role of this neuropeptide in sleep regulation. For quantifying orexin-A levels, radioimmunoassays have been the standard technique. However, these assays involve the use of radioisotopes (RIs),and thus, only a limited number of research institutions have been able to use them.
We have an ELISA kit available for easily determining orexin-A concentrations in human and rat samples, without the use of RIs.