# US 7,611,834 B2 · Methods and devices for protein assays

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- Number: US 7,611,834 B2
- Document ID: US7611834B2
- Status: Granted
- Kind: B2
- Application number: 11/239,387
- Filed: 2005-09-30
- Published: 2007-10-04
- Granted: 2009-11-03
- Earliest claimed: 2005-09-30
- Assignees: Sandia Corporation
- Inventors: Swapnil Chhabra; José´ M. Cintrón; Renée Shediac
- Web page: https://patentgrep.com/patent/US7611834B2

## CPC

- G01N 33/6806: {Determination of free amino acids}
- G01N: INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES (measuring or testing apparatus or processes other than immunoassay, involving enzymes or microorganisms C12M, C12Q)

## Abstract

Methods and devices for protein assays based on Edman degradation in microfluidic channels are disclosed herein. As disclosed, the cleaved amino acid residues may be immobilized in an array format and identified by detectable labels, such as antibodies, which specifically bind given amino acid residues. Alternatively, the antibodies are immobilized in an array format and the cleaved amino acids are labeled identified by being bound by the antibodies in the array.

## Claims

### Claim 1

An assay comprising
subjecting a protein to consecutive coupling and cleaving steps to result in a plurality of cleaved amino acid residues in a microfluidic device,
contacting each cleaved amino acid residue with a plurality of antibodies, which each antibody specifically binds a given amino acid,
identifying each cleaved amino acid residue by the antibody bound thereto, and
identifying the location of each cleaved amino acid residue in the sequence of the protein.

### Claim 2 (depends on 1)

The assay of claim 1, wherein each antibody is conjugated to a detectable label.

### Claim 3 (depends on 1)

The assay of claim 1, wherein the cleaved amino acid residues are immobilized in a microchannel in an array based on its time of cleavage in the consecutive coupling and cleaving steps.

### Claim 4 (depends on 1)

The assay of claim 1, wherein the antibodies are immobilized in an array in parallel microchannels.

### Claim 5 (depends on 3)

The assay of claim 3, which further comprises obtaining at least 19 parallel microchannels.

### Claim 6 (depends on 3)

The assay of claim 3, wherein the each antibody is conjugated to a distinguishable label and the antibodies are contacted with the cleaved amino acid residues at substantially the same time in one step and then each cleaved amino acid residue and its location are identified.

### Claim 7 (depends on 3)

The assay of claim 3, wherein each antibody is sequentially contacted with the cleaved amino acid residues and the cleaved amino acid residues and their locations are identified by deduction after contact with each antibody.

### Claim 8 (depends on 5)

The assay of claim 5, wherein each antibody is contacted with the plurality of cleaved amino acid residues in one parallel microchannel and then each amino acid residue and its location are identified.

### Claim 9 (depends on 4)

The assay of claim 4, wherein each cleaved amino acid residue is contacted with the plurality of antibodies in one parallel microchannel and then each amino acid residue and its location are identified.

### Claim 10 (depends on 1)

The assay of claim 1, wherein the cleaved amino acid residues and their locations are identified by sequentially detecting each cleaved amino acid by chromatography.

### Claim 11

A microfluidic device comprising
at least one microchannel having an amino acid residue bound to an antibody that specifically binds the amino acid residue and said antibody is conjugated to a detectable label.

### Claim 12 (depends on 11)

The microfluidic device of claim 11, and further comprising one or more parallel microchannels.