Search PubMed⌕ Search
Home/Archive/PubMed

PubMed · 807849

[Fluorescence bacterioscopy, a direct method for bacteriological food analysis].

S A Afifi·G Müller
View original source ↗Export metadata ↓

Abstract

The present bacteriological method which is intended for the simultaneous direct detection of live and dead germs in foods, offers certain difficulties in differentiating between bacterial cells and food consituents of similar forms. Furthermore, gram-negative germs are not disclosed. To overcome these difficulties, the authors performed comparative model experiments with Gram's stain and the fluorescence method, including pure cultures and foods of animal and vegetable origin. Among the fluorochromes tested (primuline, auramine, acridine orange and acridine yellow), acridine yellow has proved to be specially suited and superior to Gram's stain. A method is described which is termed fluorescence bacterioscopy. Its advantages and disadvantages are discussed.

Explore related subjects

AcridinesAnimalsBacillus subtilisBacteriaBenzophenoneidumCattleEvaluation Studies as TopicFood MicrobiologyFruitInfant FoodLactobacillusMeatMicroscopy, FluorescenceMicroscopy, Phase-ContrastSwineVegetablesEnglish AbstractJournal Article

Keep this discovery

Explore connections, maps & timelines

BibTeXRIS

S A Afifi, G Müller. 1975. [Fluorescence bacterioscopy, a direct method for bacteriological food analysis].. https://pubmed.ncbi.nlm.nih.gov/807849/

Cite the original work for its findings. Save a collection to share your selection of sources.

KEEP EXPLORING

Related citations

PubMed2007

A novel methodological approach for the analysis of host-ligand interactions.

Traditional analysis of drug-binding data relies upon the Scatchard formalism. These methods rely upon the fitting of a linear equation providing intercept and gradient data that relate to physical properties, such as the binding constant, cooperativity coefficients and number of binding sites. However, the existence of different binding modes with different binding constants makes the implementation of these models difficult. This article describes a novel approach to the binding model of host-ligand interactions by using a derived analytical function describing the observed signal. The benefit of this method is that physically significant parameters, that is, binding constants and number of binding sites, are automatically derived by the use of a minimisation routine. This methodology was utilised to analyse the interactions between a novel antitumour agent and DNA. An optical spectroscopy study confirms that the pentacyclic acridine derivative (DH208) binds to nucleic acids. Two binding modes can be identified: a stronger one that involves intercalation and a weaker one that involves oriented outer-sphere binding. In both cases the plane of the bound acridine ring is parallel to the nucleic acid bases, orthogonal to the phosphate backbone. Ultraviolet (UV) and circular dichroism (CD) data were fitted using the proposed model. The binding constants and the number of binding sites derived from the model remained consistent across the different techniques used. The different wavelengths at which the measurements were made maintained the coherence of the results.

Acridines↗