COTTON THREAD AS A LOW-COST MULTI-ASSAY DIAGNOSTIC PLATFORM

• US 20110189786A1
• Filed: 03/27/2009
• Published: 08/04/2011
• Est. Priority Date: 03/27/2008
• Status: Active Grant

• Current Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Original Assignee: President and Fellows of Harvard College (Harvard Corporation)
• Inventors: Reches, Meital, Butte, Manish J., Whitesides, George M., Dickey, Michael D.
• Granted Patent: US 8,206,992 B2
• Time in Patent Office: Days
• US Class Current: 436/164
• CPC Class Codes: B01L 2200/0605 Metering of fluids
• CPC Class Codes: B01L 2200/10 Integrating sample preparation and analysis in single entity, e.g. lab-on-a-chip concept
• CPC Class Codes: B01L 2300/0825 Test strips
• CPC Class Codes: B01L 2300/0845 Filaments, strings, fibres, i.e. not hollow
• CPC Class Codes: B01L 2300/087 Multiple sequential chambers
• CPC Class Codes: B01L 2300/12 Specific details about materials
• CPC Class Codes: B01L 2300/161 Control and use of surface tension forces, e.g. hydrophobic, hydrophilic
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/5023 with a sample being transported to, and subsequently stored in an absorbent for analysis
• CPC Class Codes: B01L 3/5088 confining liquids at a location by surface tension, e.g. virtual wells on plates, wires B01L3/50857 takes precedence
• CPC Class Codes: G01N 33/54386 Analytical elements

Abstract

Hydrophilic threads as platforms for inexpensive, low volume, portable diagnostic systems, and methods of making the same are described. A diagnostic system includes a hydrophilic loading thread having an inlet zone at a proximal end; a testing zone at a distal end; and an intermediate zone located between the inlet zone and the testing zone, wherein the testing zone does not directly contact the inlet zone. In another aspect, a diagnostic system includes (i) a hydrophilic loading thread that includes an inlet zone at a proximal end and an intermediate zone at a distal end; and (ii) one or more additional hydrophilic threads that contact the intermediate zone of the loading thread. A method of detecting the presence or absence of an analyte in a fluid sample includes applying the sample to an inlet zone of a diagnostic system that includes a hydrophilic loading thread with an inlet zone at a proximal end; an intermediate zone; and a testing zone at a distal end; wherein the testing zone does not directly contact the inlet zone.

Claims

1-38. -38. (canceled)

39. A system for performing an assay on a sample comprising one or more hydrophilic testing threads defining a sample inlet zone at a proximal end, an intermediate zone distal to the inlet zone through which fluid sample is carried by capillary action, and a testing zone distal to the intermediate zone and comprising a detection reagent which reacts with a predetermined analyte to produce a detectable signal.

40. The system of claim 39 further comprising a housing for support of the hydrophilic testing thread.

41. The system of claim 39, wherein the signal is detectable by a naked eye or a spectrometer.

42. The system of claim 40 wherein at least a portion of the hydrophilic testing thread is enclosed within the housing to protect the hydrophilic testing thread from contamination and mechanical damage.

43. The system of claim 40 wherein the housing comprises two faces, and the hydrophilic testing thread is sewn into the housing and exposed on each face.

44. The system of claim 40 wherein the testing zone is enclosed within and visible from outside the housing.

45. The system of claim 39 wherein the detection reagent is a colorimetric detection reagent.

46. The system of claim 39 comprising an array of hydrophilic testing threads for performing multiple assays on a biological sample.

47. The system of claim 39 comprising a portion of a bandage or cloth.

48. The system of claim 39 comprising a portion of a woven array of hydrophilic testing threads.

49. The system of claim 40 comprising a portion of a woven array of hydrophilic testing threads.

50. The system of claim 39 wherein a said hydrophilic testing thread comprises multiple testing zones or multiple inlet zones.

51. The system of claim 40 wherein a said hydrophilic testing thread comprises multiple testing zones or multiple inlet zones.

52. The system of claim 39 for performing multiple assays on a sample further comprising

a housing, a hydrophilic loading thread comprising an inlet zone outside the housing, where one or more said hydrophilic testing threads communicate with said loading thread and at least a portion of the testing threads is enclosed within the housing.

53. The system of claim 52 further comprising in a said testing zone a detection reagent which reacts with a predetermined analyte to produce a signal apparent to the naked eye.

54. The system of claim 52 wherein at least two testing zones comprise different detection reagents.

55. A method of detecting an analyte in a fluid sample, the method comprising contacting an inlet zone of a system of claim 39 with a sample to induce sample flow by capillary action to a said testing zone and visually observing a signal at said testing zone.

56. The method of claim 55 comprising visually observing a plurality of signals at multiple detection zones.