A widely applicable analytical system for biological stains: reverse-phase thin layer chromatography.

The suitability of reverse-phase thin layer chromatography using a commercial adsorbant and aqueous methanol as an analytical tool for biological stains was investigated. The wide range of applicability of this technique is shown by the fact that of 120 dyes used as biological stains, 84 of diverse chemical character were successfully chromatographed by varying only the water content of the eluent. Unsuccessful chromatography was due either to immobility or streaking.

Variation between different samples of SITS with respect to axonal transport and toxicity.

Retrograde axonal transport of the fluorescent compound SITS has been described as occurring only from axon terminals and not from axons of passage. Injection of 4 different commercially available samples of SITS into terminations of cerebellar pathways in the rat revealed that only one sample produced retrogradely labelled neurones. Chemical analysis suggested that this was due to a unique fluorescent component (not SITS).

Chloramphenicol acetyltransferase may confer resistance to fusidic acid by sequestering the drug.

Enterobacterial chloramphenicol acetyltransferase bound fusidic acid with high affinity, but did not acetylate the drug at an experimentally detectable rate. The enzyme may therefore confer resistance to fusidic acid by sequestering the drug and thereby preventing the drug from binding to translational elongation factor G.

The aging of Gomori's aldehyde-fuchsin: the nature of the chemical changes and the chemical structures of the coloured components.

The chemical nature of Gomori's aldehyde-fuchsin (GAF) prepared by the method of Mowry et al. (1980) was studied by monitoring the staining characteristics and various chemical properties of ripening GAF solutions. Hydrophilic-hydrophobic characteristics were assessed by reverse-phase thin-layer chromatography; overall molecular sizes, and also the sizes of the conjugated systems, were investigated using hydrophobic gel-filtration.

Rosanilins: indicator dyes for chloramphenicol-resistant enterobacteria containing chloramphenicol acetyltransferase.

Rosanilin dyes such as crystal violet and basic fuchsin have been used as indicator dyes in solid growth medium for chloramphenicol-resistant enterobacterial colonies containing the enterobacterial resistance enzyme chloramphenicol acetyltransferase (CAT). On certain media containing rosanilins, cells containing CAT formed darker colonies than cells not containing CAT. Contrast was affected by the types and concentrations of complex nutrients, sugars salts, and rosanilin dyes present.

Pyridones as potential antitumor agents II: 4-Pyridones and bioisosteres of 3-acetoxy-2-pyridone.

Pyridone structural requirements for activity against murine P-388 leukemia have been extended to isosteric analogs of 3-hydroxy-4-pyridone, a compound previously found to have activity. An amino group can be substituted for the 3-hydroxyl function with retention of activity. A sulfur, but not an amino function, can replace the lactam oxygen in the 2-position.