Method and device for detecting bacteriophage using contrast-coloring and precipitable dyes

Abstract

The use of a precipitable dye and a contrast-coloring dye together enhance visualization of plaques in confluent lawns of bacteria in bacteriophage and bacteria assays. A test sample suspected of containing a bacteriophage is combined with bacteria capable of replicating the bacteriophage, and applied to a water-proof surface to form a support for bacterial growth. The support is provided with the contrast-coloring dye and precipitable dye, and nutrients and salts capable of supporting growth of the bacteria. A lawn of bacteria is formed on the support, and plaques detected on the lawn indicate presence of the bacteriophage. The plaques contain a precipitate formed by enzymatic cleavage of the precipitable dye by an enzyme of the bacterial lawn. A similar procedure is used for detecting bacteria, except that a test sample suspected of containing a bacteria is combined with bacteriophage capable of replicating in the bacteria, and plaques detected indicate presence of the bacteria. The bacteriophage and bacteria assays are carried out with a disposable device containing at least one well having a water-proof surface and a depth of about at least 5 millimeters. A hydratable material containing the contrast-coloring dye and precipitable dye is positioned on the surface. The well may contain substantially vertical sides with a removable cover resting on top of the sides.

Dependencies are inferred from the claim text.