[Spectral and photometric characteristics of different batches of auramine O (OO)]

The spectra of absorption and fluorescence of Auramine O (OO) specimens in water solution and in cells, stained with Schiff-type auramine-SO2 reagents for DNA, were investigated. Using different specimens of the stain the accuracy and sensitivity of the cytofluorometric method were estimated by the next parameters: the value of the useful signal from the nucleus (no), the value of the production of no by the time constant of fading (tau), the value of proportion of the signal to the background (no/nphi) and, in addition, the value of the variation coefficient under the measurement of the rat liver tetraploid cells. The purity of the dye was shown to interfere largely with accuracy and sensitivity of the above method. Auramine 00 of the Reanal production appeared to have the best photometricl characteristics. For this, the maxima of the absorption spectrum in the 320--700 nm region in the solution and in the cell were 371 and 433 nm, and 375 and 436 nm, resp. The maximum of the fluorescence spectrum was found 521 nm and 526 nm, resp. for the solution (0.02%) and for the Auramine-SO2 treated cells. Moreover, an isomer of Auramine O (00) -- Auramine G can be used for detection and photometrical measurement of DNA and glycogen after the Feulgen and PAS reactions, resp.