Magnetic means for withdrawing magnetic gel beads from an assay fluid

• US 4,649,116 A
• Filed: 10/29/1984
• Issued: 03/10/1987
• Est. Priority Date: 10/27/1983
• Status: Expired due to Fees

• Current Assignee: Institut Pasteur
• Original Assignee: Institut Pasteur
• Inventors: Assimon, Andre, Daty, Jean
• Primary Examiner(s): Green, Randall L.
• Application Number:
  US06/666,263
• Time in Patent Office: 862 Days
• Field of Search: 435/287, 294/65.5, 335/293, 335/295, 335/286, 335/285, 422/186.01, 210/222
• US Class Current: 435/287.2
• CPC Class Codes: B01J 2219/00468 by manipulation of individual beads
• CPC Class Codes: B01J 2219/005 Beads
• CPC Class Codes: B03C 1/284 with associated cleaning means, e.g. retractable non-magnetic sleeve
• CPC Class Codes: B25B 11/002 Magnetic work holders
• CPC Class Codes: G01N 33/54326 Magnetic particles
• CPC Class Codes: G01N 35/0098 involving analyte bound to insoluble magnetic carrier, e.g. using magnetic separation magnetic particles used in immunoassays G01N33/54326; magnetic separation in general B03C
• CPC Class Codes: H01F 7/04 Means for releasing the attractive force

Abstract

Magnetic device for withdrawing magnetic gel beads or the like from a biological fluid and transferring them to an immunoenzymatic assay medium. This device includes a housing of insulating material, particularly of plastic material, into which is inserted a magnet and over the height of which is formed a traversing orifice in which is housed a rod formed of a lower portion of magnetizable material and an upper portion of non-magnetizable material on which is mounted a return spring, between a stop washer fixed in the vicinity of the upper end of the rod and the upper surface of the housing. The device can advantageously be included in a ready-for-use kit for carrying out immunoenzymatic assays.

Claims

1. A magnetic device for withdrawing magnetic gel beads or the like from a biological fluid and transferring the same into an immunoenzymatic assay medium, comprising in combination:

a housing of non-magnetic material which is constructed in the form of an insulating handle of said device and in which is formed a traversing orifice over its entire height, said traversing orifice being eccentric with respect to the vertical axis of the housing,

a magnetic eccentrically housed in said housing with respect to the vertical axis of this latter,

a rod housed in said eccentric traversing orifice, said orifice constituting a guide track for said rod, wherein said rod comprises an upper portion of non-magnetic material and a lower portion of magnetizable material, the latter having two limiting positions, namely a retracted position, in which the magnetizable portion is under the magnetic influence of said magnet so as to exert a magnetic force, and a projected position, in which the magnetizable portion is beyond the magnetic influence of the magnet, and detachable fixing means for fastening said lower magnetizable portion of the rod to said upper non-magnetic portion of said rod such that said lower magnetizable portion is detachable from said upper non-magnetic portion of said rod,

manually operable means for bringing said lower magnetizable portion of said rod into said projected position, and

spring means for maintaining said lower magnetizable portion of said rod in said retracted position and to move said rod back into said retracted position after releasing said manually operable means.

2. An assembly for use in performing immunoenzymatic assays, comprising:

a receptacle containing a suitable amount of magnetic gel beads or the like coupled with an antigen or a specific antibody,

a magnetic device for withdrawing said magnetic gel beads from said receptacle and transferring the same into an immunoenzymatic assay medium,

a culture dish having a lower surface provided externally with a high power magnet,

a receptacle containing a suitable amount of culture medium for the culture of pathogenic germs to be assayed, to be introduced into said culture dish,

a receptacle containing a suitable amount of an antibody or a specific pathogenic anti-germ antigen to be detected, for introduction onto said culture medium,

a receptacle containing a suitable amount of lysis agents of the pathogenic germ cultures developed in said culture dish, and

a receptacle containing a suitable amount of buffered physiological wash water wherein said magnet device comprises in combination;

a housing of non-magnetic material which is constructed in the form of an insulating handle of said device and in which is formed a traversing orifice over its entire height, said traversing orifice being eccentric with respect to a vertical axis of the housing,

a magnet eccentrically housed in said housing with respect to the vertical axis of the latter,

a rod housed in said eccentric traversing orifice, said orifice constituting a guide track for said rod, wherein said rod comprises an upper portion of non-magnetic material and a lower portion of magnetizable material, the latter having two limiting positions, namely a retracted position, in which the magnetizable portion is under the magnetic influence of said magnet, and a projected position, in which the magnetizable portion is beyond the magnetic influence of the magnet, and means for detachably fastening said said lower magnetizable portion of the rod to said upper non-magnetic portion of said rod such that said lower magnetizable portion is detachable from said upper non-magnetic portion of said rod,

manually operable means for bringing said lower magnetizable portion of said rod into said projected position, and

spring means for maintaining said lower magnetizable portion of said rod into said retracted position and to move said rod back into said retracted position after releasing said manually operable means.