Nitric oxide measurements in biological samples.

The crucial role of nitric oxide (NO) in controlling many physiological functions in mammals is now established. To aid understanding this crucial role, sensitive and selective methods for its in vivo and in vitro detection are vital. The unique chemical and physical properties of NO set the tone for its detection strategies. This review summarizes different techniques and methodologies used in measuring NO in biological samples. Those include gas and liquid phase chemiluminescence, electron spin resonance spectroscopy, UV-visible spectroscopy, fluorescence, electrochemical sensors, and reporter cell assay. The principles, applications, merits, and limitations of each technique are discussed.