Ultrasensitive detection of beta hemolytic Streptococcus
AssigneeWoundchek Laboratories (US), Inc.
InventorsMitchell C. Sanders, Dale Macy, Andrei Rakitin, Courtney Mankus
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Abstract
The present invention is directed to a method for the ultrasensitive detection of beta hemolytic Streptococcus, a bacterium implicated in strep throat, using a specific protease marker. Also disclosed is a device as well as a biosensor, both of which are useful for the detection of beta hemolytic Streptococcus. The biosensor and the device can be used in conjunction with other reagents as part of a kit for detecting strep throat.
Claims30
A device for detecting the presence or absence of a bacterium in a sample, comprising:
- (a) a reaction chamber configured to hold the sample and comprising a first amplifier configured to release a substrate in response to an enzyme produced and/or secreted by the bacterium;
- (b) a membrane;
- (c) a second amplifier in fluid communication with the first amplifier, configured to bind to the released substrate and to produce a signal in the presence of the bacterium;
- and
- (d) a lateral flow cassette comprising a conjugate pad in fluid communication with the membrane, a lateral flow strip, and a wicking pad;
- wherein the membrane is configured to allow the sample to flow to the conjugate pad and lateral flow strip under conditions that allow the released substrate to bind to the second amplifier, wherein the membrane or conjugate pad filters the first amplifier away from the released substrate such that the first amplifier is prevented from entering the lateral flow strip, and wherein the lateral flow strip is configured to indicate the signal in the presence of the bacterium.
A method for detecting the presence or absence of a bacterium in a sample using a lateral flow device comprising:
- an enzyme reaction chamber having a membrane, wherein the membrane of the enzyme reaction chamber filters released substrate away from any unreleased substrate;
- and a lateral flow cassette comprising a conjugate pad in fluid communication with the membrane, a lateral flow strip, a wicking pad, and a flow strip chamber;
- the method comprising:
- a) contacting the sample with a first amplifier in the enzyme reaction chamber under conditions that result in release of a substrate from the first amplifier in response to an enzyme produced and/or secreted by the bacterium;
- b) collecting the released substrate onto a second amplifier in the enzyme reaction chamber under conditions that allow the released substrate to bind to the second amplifier;
- c) allowing the sample to flow from the enzyme reaction chamber onto the conjugate pad, and
- d) detecting the presence of a signal on the flow strip, wherein the presence of the signal indicates the presence of the bacterium in the sample and absence of a signal on the flow strip indicates the absence of the bacterium in the sample.
Dependencies are inferred from the claim text.