# US 2013/0277232 A1 · Multiple layer gel > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 2013/0277232 A1 - Document ID: US20130277232A1 - Status: Published application - Kind: A1 - Application number: 13/866,503 - Filed: 2013-04-19 - Published: 2013-10-24 - Earliest claimed: 2012-04-19 - Assignees: Luoxis Diagnostics, Inc. - Applicants: Luoxis Diagnostics, Inc. - Inventors: Raphael Bar-Or; David Bar-Or; Leonard T. Rael - Web page: https://patentgrep.com/patent/US20130277232A1 ## CPC - G01N 27/4168: {Oxidation-reduction potential, e.g. for chlorination of water (water analysis G01N33/18)} - G01N 27/301: {Reference electrodes} - G01N 27/406: Cells and probes with solid electrolytes - G01N 33/48707: {by electrical means (G01N33/49, G01N33/493 take precedence)} - G01N 27/3272: {Test elements therefor, i.e. disposable laminated substrates with electrodes, reagent and channels (optical biosensors G01N33/52)} - G01N 27/403: Cells and electrode assemblies - 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 A multiple layer gel and method for forming a multiple layer gel are provided. The multiple layer gel includes an isolation layer and an electrolyte layer. The isolation layer provides a molecular weight screen, to prevent proteins or other molecules from contacting a reference cell covered by the isolation layer. The electrolyte layer covers the isolation layer, and provides a source of ions that place the reference cell in ionic and/or electrical contact with a fluid sample. The multiple layer gel can be used to maintain a reliable reference voltage from an associated reference cell while an electrical potential or other electrical characteristic of a sample fluid is being determined. ## Claims ### Claim 1 An oxidation-reduction potential test device, comprising: a substrate; a spacer layer interconnected to at least a portion of the substrate, wherein the spacer layer defines a sample chamber; a test strip overlay, wherein the test strip overlay is interconnected to at least a portion of the spacer layer; a first test lead supported by the substrate, the first test lead including: a first area extending into the sample chamber; a second area extending from the sample chamber to a readout region; a second test lead supported by the substrate, the second test lead including: a first area extending into the sample chamber; a second area extending from the sample chamber to a readout region; a reference cell; a reference lead, including; a first area in electrical contact with the reference cell; a second area extending from the reference cell to a readout region; a filter, wherein at least a portion of the filter overlaps at least a portion of each of the first area of the first test lead, the first area of the second test lead, and the first area of the reference lead; and a gel volume, wherein the gel volume includes a first layer in contact with the reference cell and a second layer over the first layer, and wherein the first layer differs in composition from the second layer. ### Claim 2 (depends on 1) The device of claim 1, wherein the first layer comprises an agarose and hydroxyethyl cellulose layer, and wherein the second layer comprises an agarose and KCl layer. ### Claim 3 (depends on 1) The device of claim 1, wherein the first layer comprises about a water based gel containing about 4% agarose and about 1% hydroxyethyl cellulose, and wherein the second layer comprises a water based get containing about 4% agarose and about a 3M concentration of KCl. ### Claim 4 (depends on 1) The device of claim 1, wherein at least a portion of the first test lead, the reference cell, at least a portion of the reference lead, and the bridge are between the substrate and the overlay when the overlay is interconnected to the substrate, wherein the overlay includes an aperture, wherein the aperture corresponds to at least a portion of the sample chamber when the overlay is interconnected to the substrate, wherein the filter is at least partially contained within the sample chamber, and wherein the gel volume is in communication with the sample chamber. ### Claim 5 (depends on 1) The device of claim 1, wherein the reference cell includes a silver/silver chloride reference cell. ### Claim 6 (depends on 1) The device of claim 1, further comprising: a fluid sample, wherein the fluid sample comprises a wetting agent that wets the filter that electrically interconnects the first area of the first test lead, the first area of the second test lead, and the first area of the reference lead. ### Claim 7 (depends on 6) The device of claim 6, wherein the fluid sample is whole blood. ### Claim 8 (depends on 1) The device of claim 1, wherein the first test lead, the second test lead, and the reference lead are formed from an electrically conductive material having a constant composition. ### Claim 9 (depends on 8) The device of claim 8, wherein the electrically conductive material having a constant composition is platinum. ### Claim 10 (depends on 1) The device of claim 1, wherein the first test lead, the second test lead, and the reference lead are accessible to a test device in the readout region when the overlay is interconnected to the substrate. ### Claim 11 (depends on 1) The device of claim 1, wherein the first test lead, the second test lead, and the reference lead are located on a common plane. ### Claim 12 (depends on 1) The device of claim 1, wherein the first layer is an isolation layer, and wherein the second layer is an electrolyte layer. ### Claim 13 (depends on 12) The device of claim 12, wherein the isolation layer is a molecular screening layer. ### Claim 14 (depends on 12) The device of claim 12, wherein the electrolyte layer is a source of chloride ions. ### Claim 15 A method for forming a multiple layer gel, comprising: providing a test strip substrate that includes a plurality of test leads and a reference cell; applying an isolation layer over the reference cell; and applying an electrolyte layer over the isolation layer. ### Claim 16 (depends on 15) The method of claim 15, wherein applying an isolation layer includes applying a gel containing agarose and hydroxyethyl cellulose (HEC) over the reference cell. ### Claim 17 (depends on 16) The method of claim 16, wherein the isolation layer is applied using a heat block technique. ### Claim 18 (depends on 17) The method of claim 17, wherein applying an electrolyte layer includes applying a gel containing 3% HEC in 3M KCl over the isolation layer. ### Claim 19 (depends on 17) The method of claim 17, wherein after applying the isolation layer the test strip is allowed to dry at ambient temperature, and wherein after applying the electrolyte layer the test strip is placed in a pre-heated vacuum oven at 0.02 MPa below atmospheric pressure. ### Claim 20 A multiple layer gel, comprising: an isolation layer, wherein the isolation layer is a molecular weight screening layer; an electrolyte layer, wherein the electrolyte layer is a source of ions.