A novel method of measuring gas phase nitric oxide concentration in cell cultures

This is the first report on the measurement of nitric oxide (NO) concentrations in the gas phase in a squamous cell culture. The technique may permit the assessment of NO output under conditions that aim to mimic facets of pathology in relatively inaccessible tissues. The primary aim of this study was to devise a method to detect the NO concentration produced by cell cultures in the gas phase of a culture flask. A secondary aim was to determine whether the effect of hypoxia or radiation on NO production in a human squamous cell carcinoma cell culture would be detectable with this technique. The NO concentration was measured off-line using a rapid-response chemiluminescent analyzer. The gas samples were aspirated from cell culture flasks (i) under normal culture conditions, (ii) under conditions of hypoxia and (iii) following radiation of human head and neck squamous cell carcinoma cell line cultures. Elevated levels of the gas phase NO concentration were consistently obtained from the cell culture flasks using this experimental set-up. Hypoxia and radiation diminished NO production.