Cornell Research Foundation Inc.

Innovative Biotechnologies, Inc.

Other

Richard Allen Durst

Matthew A Roberts

Richard A Montagna

Geoffrey S Rule

Sui Ti Atienza Siebert

Stuart Graham Reeves

Daniel Martorell-Pena

Sui Ti Siebert

Sui Ti A Siebert

Antje J B&auml;umner

The present invention relates to a method for making a test device for detecting or quantifying an analyte in a sample. This method involves contacting a membrane with a mixture including derivatized, marker-loaded liposomes, and substantially dehydrating the mixture on the membrane under vacuum pressure at a temperature of from about 4&#xb0; C. to about 80&#xb0; C., wherein said mixture further includes one or more sugars in an amount sufficient to promote the stability of the liposomes during dehydration and rehydration. The present invention also relates to a test device and method for detecting or quantifying an analyte in a sample. The test device includes a membrane which includes an immobilized liposome zone, wherein the immobilized liposome zone has bound thereto dehydrated, derivatized, marker-loaded liposomes dehydrated under vacuum pressure at a temperature of from about 4&#xb0; C. to about 80&#xb0; C. from a mixture which includes one or more sugars in an amount sufficient to promote the stability of the liposomes during dehydration and rehydration.

Dehydration/rehydration of derivatized, marker-loaded liposomes on a test device and method of use thereof

Method of making a test device

A test device and method for detecting or quantifying an analyte in a test sample employs an interdigitated electrode array and electroactive marker-encapsulating liposomes for signal generation and detection. The test device includes a contact portion on a first absorbent material, a capture portion either on the first absorbent material, or on a second absorbent material in fluid flow contact with the first absorbent material. The capture portion has a binding material specific for a portion of the analyte bound thereto. The device further includes an electrode array including first and second conductors each having a plurality of fingers, wherein the fingers of the conductors are interdigitated. The electrode array is positioned to induce redox cycling of an electroactive marker released either in or beyond the capture portion, depending upon whether direct (proportional) or indirect (inversely proportional) detection or measurement is desired. In the method of the invention, the test sample is applied to the contact portion, and allowed to migrate along the absorbent material(s) into the capture portion. Either before or after the migration, the test sample is contacted with a conjugate of liposomes and a second binding material for the analyte. To the extent that analyte is present in the sample, the conjugate is bound in the capture portion. By applying a voltage across the conductors, redox cycling of the marker is induced and a current is generated.

Liposome-enhanced test device and method

A test device for detecting or determining an analyte in a test solution includes an absorbent material having separate contact, competitive binding, and measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The competitive binding portion has a binding material for the analyte non-diffusively bound thereto. The measurement portion has a receptor for the analyte and marker-encapsulating liposomes non-diffusively bound thereto. In a method for using the test device, a solution containing the analyte and the analyte-liposome conjugate is allowed to traverse the absorbent material from the contact portion through the competitive binding portion and on through the measurement portion of the absorbent material. The amount of marker in the measurement portion of the absorbent material, following traversal by the test solution, is then determined as a measure of the analyte in the sample. Liposomes encapsulating an electroactive marker are used in conjunction with a test device as described above but which includes an electrochemical measurement portion in place of the measurement portion described above. Test devices and methods employing electrochemical detection or quantification of an electroactive marker corresponding to the amount of analyte in a sample may be either amperometric or potentiometric.

Liposome-enhanced immunoassay and test device

A test device for detecting or quantifying determining an analyte in a test solution includes an absorbent material having contact, liposome lysing and electrochemical measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The liposome lysing portion is segregated from the contact portion and has a liposome lysing agent bound thereto. The liposome lysing portion is further either positioned between the contact portion and the electrochemical measurement portion, or partially or completely coincides with the electrochemical measurement portion. The electrochemical measurement portion comprises a first conductor comprising a plurality of fingers disposed on the absorbent material, and a second conductor similarly comprising a plurality of fingers disposed on the absorbent material, where the fingers of the first and second conductors are interdigitated to form an array. The capture portion has a capture probe designed to at least partially hybridize with a portion of the target nucleic acid sequence bound thereto.

Interdigitated electrode arrays for liposome-enhanced immunoassay and

A test device for detecting or quantifying an analyte in a test sample includes an absorbent material having separate contact and measurement portions. The contact portion is positioned at or proximate to a first end of the absorbent material. The measurement portion has a receptor for a conjugate of an analyte analog and marker-encapsulating liposomes. In a method for using the test device, a binding material specific for the analyte is combined with the liposome-analyte analog conjugate and the test sample to form a test mixture. The mixture is incubated for a time sufficient to permit competition between any analyte present and the conjugate for the binding material. Following incubation, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material. Following traversal by the test mixture, the presence or amount of marker in the measurement portion of the absorbent material is then detected and correlated with the presence or amount, respectively, of the analyte in the sample. Liposomes encapsulating an electroactive marker are used in conjunction with a test device as described above but which includes an electrochemical measurement portion in place of the measurement portion described above. Test devices and methods employing electrochemical detection or quantification of an electroactive marker corresponding to the amount of analyte in a sample may be either amperometric or potentiometric.

Liposome enhanced immunoaggregation assay and test device

A test device for detecting or determining an analyte in a test solution includes an absorbent material having contact, liposome lysing and electrochemical measurement portions. The contact portion is positioned for contact with and uptake of the test solution. The liposome lysing portion is segregated from the contact portion and has a liposome lysing agent bound thereto. The liposome lysing portion is further either positioned between the contact portion and the electrochemical measurement portion, or partially or completely coincides with the electrochemical measurement portion. The electrochemical measurement portion comprises a first conductor comprising a plurality of fingers disposed on the absorbent material, and a second conductor similarly comprising a plurality of fingers disposed on the absorbent material, where the fingers of the first and second conductors are interdigitated to form an array.

Liposome-enhanced immunoaggregation assay and test device

A test device for detecting or quantifying an analyte in a test sample includes an absorbent material having separate contact and measurement portions. The contact portion is positioned at or proximate to a first end of the absorbent material. The measurement portion has a receptor for a conjugate of an analyte analog and marker-encapsulating liposomes. In a method for using the test device, a binding material specific for the analyte is combined with the liposome-analyte analog conjugate and the test sample to form a test mixture. The mixture is incubated for a time sufficient to permit competition between any analyte present and the conjugate for the binding material. Following incubating, the mixture is allowed to traverse the absorbent material from the contact portion through the measurement portion of the absorbent material. Following traversal by the test mixture, the presence or amount of marker in the measurement portion of the absorbent material is then detected and correlated with the presence or amount, respectively, of the analyte in the sample. Also disclosed are liposomes encapsulating an electroactive marker used in conjunction with a test device as described, but which includes an electrochemical measurement portion in place of the measurement portion described above. Test devices and methods employing electrochemical detection or quantification of an electroactive marker corresponding to the amount of analyte in a sample may be either amperometric or potentiometric.

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Romulus, NY, United States of America

Richard Allen Durst