the interaction between isatin-β-thiosemicarbazone (ibt) and calf thymus dna (ct-dna) was investigated in physiological buffer (ph 7.4) using neutral red (nr) dye as a spectral probe by uv–vis absorption and fluorescence spectroscopy, as well as viscosity measurements. the ibt is stabilized by intercalation in the dna ( k [ibt –dna] =1.03×105 m−1), and displaces the nr dye from the nr–dna comple...

Neutral red is a dye the azine structure which has been used as an acido-base indicator and a dye in histochemistry. In 1960 Goldhaber introduced Neutral red into the medium of resorbing bone cultures to localize the osteoclast in the living cultures. Using time-lapse microcinematography in order to follow the osteoclasts, he reported excellent contrast could be obtained with Neutral red due to...

In earlier studies of the mouse pancreas (1), it was found microscopically in saline preparations of living tissue that, within 30 min after the injection of an optimum dose of neutral red, small dye granules appeared in the cytoplasm of the acinar cells. With time, the granules became larger, reached a peak development at about 7 hr, then gradually diminished in size and number until, at about...

BACKGROUND The study was aimed at investigating the effect of various solvents on the absorption spectra of Neutral Red, a dye belonging to the quinone-imine class of dyes. The solvents chosen for the study were water, ethanol, acetonitrile, acetone, propan-1-ol, chloroform, nitrobenzene, ethyleneglycol, acetic acid, DMSO and DMF. RESULTS The results have shown that the absorption maxima of d...

After treatment with neutral red at low concentrations (10(-6), 10(-5) M), the chromatin of chicken erythrocytes shows an intensive red fluorescence, which is reduced or practically abolished when nuclei become stained by using the dye at concentrations higher than 10(-4) M. Both the fluorescence and staining reactions are dependent on the DNA content of chromatin. Neutral red fluorescence of n...

I investigations carried out in this laboratory have been concerned with the initial responses of the corneal stromal cells to injury. One reaction which occurs in the stromal cells within a few hours after injury to the cornea is the activation of the fibrocytes to take up the vital dye, neutral red.' This reaction does not occur in the normal corneal stromal cells of the rat, but cells activa...

The neutral red uptake assay is a cell viability assay that allows in vitro quantification of xenobiotic-induced cytotoxicity. The assay relies on the ability of living cells to incorporate and bind neutral red, a weak cationic dye, in lysosomes. As such, cytotoxicity is expressed as a concentration-dependent reduction of the uptake of neutral red after exposure to the xenobiotic under investig...

Searching for virulence marking tests for Mycobacterium tuberculosis, Dubos and Middlebrook reported in 1948 that in an alkaline aqueous solution of neutral-red, the cells of the virulent H37Rv M. tuberculosis strain fixed the dye and became red in color, whereas the cells of the avirulent H37Ra M. tuberculosis strain remained unstained. In the 1950 and 1960s, fresh isolates of M. tuberculosis ...

The binding affinity of Neutral Red with cucurbit[7]uril (CB7) can be fine-tuned by addition and competitive binding of metal ions, which leads also to a pK(a) shift of the dye; this can be exploited to relocate the dye from the macrocyclic cavity of CB7 to the biomolecular pocket of bovine serum albumin.