Assay reagents and devices

• US 6,133,048 A
• Filed: 09/23/1997
• Issued: 10/17/2000
• Est. Priority Date: 09/27/1996
• Status: Expired due to Term

• Current Assignee: Inverness Medical Switzerland GmbH (Abbott Laboratories Incorporated)
• Original Assignee: Unilever Patent Holdings BV (Unilever PLC)
• Inventors: Percival, David A., Penfold, Yvonne E.
• Primary Examiner(s): Minnifield, Nita
• Assistant Examiner(s): BASKAR, PADMAVATHI
• Application Number:
  US08/935,537
• Time in Patent Office: 1,120 Days
• Field of Search: 436/531, 436/533, 436/534, 436/514, 436/810, 435/970, 435/805, 422/56
• US Class Current: 436/533
• CPC Class Codes: G01N 33/54393 Improving reaction conditions or stability, e.g. by coating or irradiation of surface, by reduction of non-specific binding, by promotion of specific binding
• CPC Class Codes: G01N 33/558 using diffusion or migration of antigen or antibody immunochromatographic test strips G01N33/54387
• CPC Class Codes: G01N 33/585 with a particulate label, e.g. coloured latex
• CPC Class Codes: Y10S 435/805 Test papers
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10S 436/81 Tube, bottle, or dipstick

Abstract

A reagent useful in immunoassays, comprising a direct particulate level co-sensitized with a specific binding agent having specificity for an analyte or analyte analog and with a non-specific protein which can participate in a control reaction with another specific binding agent which does not bind to the first specific binding agent nor participate in the formation of a complex by means of which detection of the analyte or analyte analog is accomplished. Preferably the first specific binding agent is an antibody raised in a first species and the non-specific protein is an immunoglobulin from another species. Optionally, the reagent additionally comprises a second population of the direct particulate label sensitized solely with the non-specific protein.

Claims

1. A reagent useful in immunoassays, comprising a direct particulate label co-sensitized with

(i) a specific binding agent having specificity for an analyte or analyte analogue, and

(ii) a non-specific protein which does not bind to said analyte or analyte analogue but can participate in a control reaction with another specific binding agent which does not bind to said first specific binding agent nor participate in the formation of a complex by means of which detection of said analyte or analyte analogue is accomplished, said specific binding agent being a murine antibody and said non-specific protein being a rabbit immunoglobulin.

2. A reagent according to claim 1, further comprising a population of direct particulate label sensitized solely with said non-specific protein.

3. A reagent according to claim 1, comprising coloured latex particles of diameter less than 0.5 micron, co-sensitised with an anti-hCG murine monoclonal antibody and with rabbit IgG.

4. A reagent according to claim 3, additionally comprising same-coloured latex particles of diameter less than 0.5 micron sensitised solely with rabbit IgG, the ratio of said co-sensitised particles to said additional latex particles being at least 2:

1.

5. A reagent according to claim 4, wherein said ratio is about 3:

1.

6. A reagent according to claim 1 wherein the quantity of specific binding agent on the co-sensitized particulate exceeds the quantity of non-specific protein therein.

7. A reagent according to claim 6 wherein the ratio of specific binding agent to non-specific protein is at least 5.1.