Formaldehyde-fluorescamine-induced fluorescence as a property of carcinoma cells

Fluorescamine is a sensitive cytochemical probe for primary amino groups and produces an intense general fluorescence in unfixed tissue sections reflecting the ubiquitous occurrence of such groups. Following treatment with formaldehyde, most primary amino groups react to form derivatives unable to yield fluorescence with fluorescamine. Certain cell systems, however, contain amino groups which do not react with formaldehyde but display strong reactivity with fluorescamine. In formaldehyde- and fluorescamine-treated specimens such cell systems display an intense fluorescence, whereas the majority of tissue constituents are non-fluorescent. Fluorescent cell systems include certain protein- and peptide-secreting cells and a large number of different types of carcinoma cells. In some cases it appears that neoplastic transformation is necessary before the cells display formaldehyde-fluorescamine-induced fluorescence. Available data indicate that the reactive substance(s) are peptide in nature and that the production of such substance(s) may be a general property of carcinoma cells.