Test device

• US 4,246,339 A
• Filed: 11/01/1978
• Issued: 01/20/1981
• Est. Priority Date: 11/01/1978
• Status: Expired due to Term

• Current Assignee: Millipore Investment Holdings, Ltd. (Merck & Co., Inc.)
• Original Assignee: Millipore Corporation (Merck & Co., Inc.)
• Inventors: Edwards, James H., Cole, Francis X., Hendrick, Clifford L., VanVoorhis, Deborah M.
• Primary Examiner(s): Wiseman, Thomas G.
• Application Number:
  US05/956,702
• Time in Patent Office: 811 Days
• Field of Search: 435/7, 435/288, 435/291, 435/287, 424/12, 23/230 B, 422/69, 422/71, 422/61, 422/101, 422/102
• US Class Current: 435/5
• CPC Class Codes: B01L 2300/0829 Multi-well plates; Microtitration plates
• CPC Class Codes: B01L 2400/0406 capillary forces
• CPC Class Codes: B01L 3/50255 Multi-well filtration
• CPC Class Codes: C12M 23/12 Well or multiwell plates C12M25/04 takes precedence
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: Y10S 436/808 Automated or kit

Abstract

A test device for assaying liquid samples for the presence of a predetermined reagent is described. The device comprises telescoping top and bottom members defining a liquid reservoir therebetween, resilient means for biasing the members in the open position, one or more test wells in the top member with bottom openings covered with microporous membranes, a co-reactant immobilized on the membrane surfaces, and sorbent means between the members spaced from the membrane(s) in the open position but in contact therewith in the closed position. Liquids are passed through the membrane(s) into the sorbent means by depressing the members to the closed position.

Claims

1. A test device for assaying a test liquid for the presence of a predetermined reactant by incubation with a coreactant therefor to form and wash a detectable reaction product, said device comprising:

top and bottom members disposed for relative movement toward and away from each other to define an open position and a closed position,

means for biasing said members in the open position,

at least one well for test liquid in the top member, said well having an open bottom,

a microporous membrane having substantially uniform pores having between about 25 nanometers and 25 micrometers sealed liquid-tight to the periphery of and extending substantially horizontally across the open bottom of the well, said well or membrane containing or constituting said coreactant,

and solid sorbent material carried by said bottom member, the major portion of said material being wettable by said liquid, the upper surface of said sorbent material being disposed for contact with the bottom of said membrane when the members are in the closed position but being removed therefrom in said open position,

whereby liquid is retained in said well when the members are in the open position but flows through the membrane into the sorbent material in the closed position.

2. A test device according to claim 1 wherein said coreactant is a biologically active material immobilized to the surfaces of said membrane.

3. An immunochemical test device according to claim 2 wherein said reactant is an antibody or antigen and said coreactant is an antigen or antibody immunochemically binding to said reactant.

4. A self-contained, disposable test device according to claim 3 wherein said biasing means comprising a resilient material disposed between the members, one of the members fitting within the peripheral margin of the other and being disposed to telescope within said other in moving from the open to the closed position.

5. A device according to claim 3 wherein said immobilized coreactant is an antigen of Toxoplasma gondii, an antibody to Hepatitis B virus, an antibody to Entomeba histolytica, Rubella antigen, nucleic acids, or human antiglobulins.

6. A test device according to any one of claims 1 to 4 having a plurality of test wells in the top member, each of said wells having a bottom opening covered by a microporous membrane having said coreactant immobilized thereon, said membranes being substantially in a common plane.

7. A test device according to any one of claims 1 to 4 wherein said sorbent means comprises a porous top layer which is substantially non-wettable by the test liquid, and a lower bulk layer which is wettable by the test liquid, whereby plurality of liquids may be sequentially passed through the membranes without substantially re-wetting them with previously sorbed liquids.

8. A test device according to claim 7 wherein said device is portable, the test wells each have a fluid capacity less than about 10 milliliters, and said sorbent material has a capacity to sorb substantially all of the liquids to be passed through the membranes.

9. A test device according to claim 7 wherein said test liquid is aqueous and the surface layer of the sorbent means is a hydrophobic material.

10. A test device according to claim 7 wherein said microporous membrane is thin and comprises at least about 60% voids by volume.

11. The method of assaying for the presence of a predetermined reactant in a test liquid which comprises:

providing a test device according to any one of claims 1, 2, 3 or 4, the top and bottom members thereof being in the biased open position,

placing test liquid in said well and incubating for a time sufficient to form said reaction product,

moving said members toward each other from the open to the closed position and allowing the test liquid to flow through the membrane into the sorbent material,

moving said members away from each other to the open position,

adding a washing liquid to said well,

moving said members toward each other from the open to the closed position and allowing the washing liquid to flow through the membrane into the sorbent material, and

determining the presence or absence of said reaction product.

12. The method according to claim 11 wherein said reaction product is the combination of an antigen and antibody bound to the surfaces of the membrane, said reaction product being determined by adding to the well with the members in the open position an enzyme conjugate binding to said reaction product, passing unreacted conjugate through the membrane into the sorbent material by moving the members to the closed position, thereafter washing the membrane by adding washing liquid to the well and passing it into the sorbent material while holding the members in the closed position, moving the members to the open position, and adding to the well a chromogen solution which changes color in the presence of said enzyme.