A quantitative gram reaction.

Crystal violet binding capacity and the Gram reaction of bacterial cells.

Kennedy and Barbaro (1953) presented data suggesting that crystal violet adsorption values correlated directly with the gram staining character of bacterial cells, and implied that such quantitative dye uptake studies might prove a basis for a much needed quantitative index of gram positivity. Their results are consistent with a popular theory of the mechanism of gram differentiation presented ...

Real-time polymerase chain reaction for quantitative detection of histamine-producing bacteria: use in cheese production.

Biogenic amines are toxic substances that appear in foods and beverages as a result of AA decarboxylation. The enzyme histidine decarboxylase catalyzes the decarboxylation of histidine to histamine, the biogenic amine most frequently involved in food poisoning. The aim of the present work was to develop a real-time quantitative PCR assay for the direct detection and quantification of histamine-...

Quantitative and Qualitative Analysis of Bacteria in Er(III) Solution by Thin-Film Magnetopheresis.

Magnetic deposition, quantitation, and identification of bacteria reacting with the paramagnetic trivalent lanthanide ion, Er, was evaluated. The magnetic deposition method was dubbed thin-film magnetopheresis. The optimization of the magnetic deposition protocol was accomplished with Escherichia coli as a model organism in 150 mM NaCl and 5 mM ErCl(3) solution. Three gram-positive bacteria, St...

Hydrophobic ionic liquids for quantitative bacterial cell lysis with subsequent DNA quantification

DNA is one of the most frequently analyzed molecules in the life sciences. In this article we describe a simple and fast protocol for quantitative DNA isolation from bacteria based on hydrophobic ionic liquid supported cell lysis at elevated temperatures (120-150 °C) for subsequent PCR-based analysis. From a set of five hydrophobic ionic liquids, 1-butyl-1-methylpyrrolidinium bis(trifluoromethy...

Quantitative Studies on the Neutralization Reaction between African Horse-sickness Virus and Antiserum