Direct stain specific binding assays for microorganisms
AssigneeQuidel Corporation
InventorsRandall D. Madsen, Lorraine S. Bautista, Jan W. Pawlak, Allan D. Pronovost
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Abstract
The present invention provides specific binding solid phase assay methods and kits for the detection of the presence or absence of a microorganism by directly staining the microorganism and specifically capturing the stained microorganism on a solid support. The methods find particular utility in the detection of Candida. The methods may simultaneously detect the presence or absence of multiple microorganisms.
Claims38
An assay for determining the presence or absence of a microorganism in a fluid sample suspected of containing a microorganism, said assay comprising:
- a) combining the sample with a labeling reagent to form a labeled microorganism, said labeling reagent comprising a dye which directly stains the microorganism to provide a stained sample comprising a stained microorganism,
- b) contacting the stained sample with a matrix defining a flow path from a sample receiving zone to a capture zone located downstream from the sample receiving zone wherein said capture zone comprises an immobilized specific binding pair member for the microorganism, and
- c) observing the accumulation of the stained microorganism within the capture zone as a result of the stained microorganism flowing into and being immobilized within the capture zone by the specific binding pair member.
An assay for determining the presence or absence of a microorganism in a fluid sample suspected of containing a microorganism, said assay comprising a means for labelling the microorganism to form a labelled microorganism, and capturing the labelled microorganism on a matrix comprising a capture zone on which is immobilized a specific binding pair member for said microorganism, wherein said labelling means comprises:
- 1) combining the sample with a dye reagent which directly stains the microorganism to provide a stained sample comprising a stained microorganism, and
- 2) neutralizing the stained sample to a physiological pH prior to capturing the stained microorganism on the capture zone;
- and relating the accumulation of the stained microorganism in the capture zone to the presence or absence of the microorganism in the sample.
In an assay for determining the presence or absence of a microorganism in a fluid sample suspected of containing a microorganism, said assay comprising a means for labelling the microorganism to form a labelled microorganism, and capturing the labelled microorganism on a matrix comprising a capture zone on which is immobilized a specific binding pair member for said microorganism, the improvement comprising a labelling means which comprises:
- 1) combining the sample with a dye reagent which directly stains the microorganism to provide a stained sample comprising a stained microorganism, and
- 2) neutralizing the stained sample to a physiological pH prior to capturing the stained microorganism on the capture zone;
- and relating the accumulation of the stained microorganism in the capture zone to the presence or absence of the microorganism in the sample.
An assay for determining the presence or absence of at least one of a plurality of microorganisms in a fluid sample suspected of containing at least one of said microorganisms, said assay comprising:
- a) combining the sample with a labelling reagent to provide a plurality of labelled microorganisms, said labelling reagent comprising a dye or mixture of dyes which directly stain the microorganisms to provide a stained sample comprising a plurality of stained microorganisms,
- b) optionally combining the stained sample with a neutralization reagent which adjusts the pH of the stained sample to a physiological pH to provide a neutralized sample,
- c) contacting the stained or neutralized sample with a matrix defining a flow path from a sample receiving zone to a plurality of capture zones located downstream from the sample receiving zone wherein each of said capture zones comprise an immobilized specific binding pair member each of which binds to a different microorganism,
- d) observing the accumulation of the stained microorganisms within the plurality of capture zones as a result of the stained microorganisms flowing into and being immobilized within the plurality of capture zones by each of the specific binding pair members, and
- e) relating the accumulation of stained microorganisms within the capture zones to the presence or absence of microorganism in the fluid sample.
A kit for detecting the presence of a microorganism in a fluid sample suspected of containing the microorganism, comprising in packaged combination:
- (a) a dye reagent capable of directly staining the microorganism, and
- (b) a matrix defining a flow path from a sample receiving zone to a capture zone located downstream from the sample receiving zone, wherein the capture zone comprises an immobilized specific binding pair member for the microorganism.
Dependencies are inferred from the claim text.