Analytical work station

• US 5,529,752 A
• Filed: 12/22/1994
• Issued: 06/25/1996
• Est. Priority Date: 01/17/1989
• Status: Expired due to Fees

• Current Assignee: Molecular Devices
• Original Assignee: Molecular Devices
• Inventors: Smith, Thomas, Ross, Debra A., Drbal, Vladimir, Chow, Calvin, Pontis, George, Kirk, Gregory, Lacy, Michael, Briggs, Jonathan, Smethers, Rick, Leytes, Lev, Mehta, Suresh N.
• Primary Examiner(s): Warden, Jill
• Assistant Examiner(s): Le, Long V.
• Application Number:
  US08/361,980
• Time in Patent Office: 551 Days
• Field of Search: 422/63, 422/99, 422/100, 422/101, 422/103, 422/104, 422/58, 422/82.05, 422/82.01, 422/82.02, 422/82.03, 422/81, 436/175, 436/46, 436/177, 436/47, 436/178, 436/48, 436/180, 436/49, 436/164, 436/165, 436/43, 436/174, 435/300, 435/301, 204/403, 204/222, 204/400
• US Class Current: 422/63
• CPC Class Codes: G01N 2035/00138 Slides
• CPC Class Codes: G01N 2035/00485 combined with sample carriers
• CPC Class Codes: G01N 33/5302 Apparatus specially adapted for immunological test procedures
• CPC Class Codes: G01N 33/54366 Apparatus specially adapted for solid-phase testing
• CPC Class Codes: G01N 35/00009 provided with a sample supporting tape, e.g. with absorbent zones
• CPC Class Codes: G01N 35/00029 provided with flat sample substrates, e.g. slides G01N35/028 takes precedence
• CPC Class Codes: Y10S 435/97 Test strip or test slide
• CPC Class Codes: Y10T 436/11 Automated chemical analysis
• CPC Class Codes: Y10T 436/112499 with sample on test slide
• CPC Class Codes: Y10T 436/25 including sample preparation
• CPC Class Codes: Y10T 436/25375 Liberation or purification of sample or separation of material from a sample [e.g., filtering, centrifuging, etc.]

Abstract

This invention encompasses a work station for conducting assays which comprises filtering assembly, a slide reading assembly, and a slide with a porous filter membrane wherein the slide has a means for aligning the slide within the filter assembly to filter reagents on predetermined portions of the porous filter membrane and also to position the slide in the slide reading assembly so that detection will occur in those same predetermined locations.

Claims

1. A slide reading assembly comprising:

(a) a housing with a top, bottom, and inner and outer sidewall sections wherein the inner side wall section has a window with a photoresponsive electrode having an inner surface mounted above the window on the inside of the inner side wall section so that light from an external source can pass into and be absorbed within the photoresponsive electrode and said outer sidewall section has a surface;

the top section of the housing having an opening for receiving a slide to be analyzed wherein the slide has a porous filter membrane with analyte to be determined on predetermined locations on the porous filter membrane, said housing having means for aligning the predetermined locations on the porous filter membrane on the inner surface of the photoresponsive electrode opposite the window in the housing which allow light to pass to a photoresponsive electrode;

a resilient plunger mounted in the outer side wall surface of the housing opposite the photoresponsive electrode, the plunger having a stem and pad such that when the plunger stem is pushed inwardly, by an operatively associated stepping motor, into the housing the pad compresses the porous membrane against the inner surface of the photoresponsive electrode;

a liquid chamber within the housing with exit and entrance ports for liquids in the top section of the housing and wherein the inner surface of the photoresponsive electrode is within the liquid chamber and the porous filter membrane is aligned above the inner surface of the photoresponsive electrode in the liquid chamber;

(b) an intensity-modulated light source for independently irradiating the photoresponsive electrode through the window in the housing on each area of the photoresponsive electrode opposite the area of the porous filter having a predetermined location of filtered analyte or analyte complex; and

(c) an electrical means for measuring a potential change of the surface of the photoresponsive electrode when the photoresponsive electrode is exposed to an intensity-modulated beam of light through the window in the housing and a chemical reaction is occurring between the filtered analyte or analyte complex on the porous filter membrane and a reagent in the liquid in the liquid chamber, the electrical means including a counter electrode, and an operation amplifier.

2. A slide reading assembly according to claim 1 wherein the inner surface of the photoresponsive electrode has a coating of insulation.

3. A slide reading assembly according to claim 1 wherein the pad of the plunger is pivotally mounted on the stem of the plunger.

4. A slide reading assembly according to claim 1 wherein the slide alignment means is a slide support member with a depression that fits the configuration of the slide and a peg that fits a notch in the slide.

5. A slide reading assembly according to claim 1 wherein the alignment means is a peg at the bottom section of the housing and a depression on a slide support member to fit the shape of the slide.

6. A slide reading assembly according to claim 1 which has a reference electrode.

7. A slide reading assembly according to claim 5, said slide comprising a thin flat generally rectangular plastic sheet with a front and rear end wherein the front end of the slide has a notch as means for aligning the slide both in a filter assembly and a reading assembly;

the rear end of the slide having an area for manually grasping the slide;

wherein the front, approximately a third of the slide, defines an opening which is covered with a porous filter membrane and a section of the front one third of the slide is narrower than the rear section of the slide, said narrower section also serving as a means for aligning the slide in both the filtering assembly and the reading assembly and wherein the alignment means provide for deposition of analyte complex onto predetermined locations on the porous filter membrane in the filter assembly and for detection of analyte complex at these same predetermined locations in the reading assembly.

8. A slide reading assembly according to claim 6 wherein the porous filter membrane has fixed to it a hapten and wherein the hapten is biotin.

9. A slide reading assembly according to claim 5 which has a buffering capacity of 1-10 m mole per liter of compressed membrane volume.

10. An analytical work station comprising one or more filtering assemblies and a slide reading assembly, said filtering assembly comprising in combination:

a block with a top and bottom surface, said block having a plurality of channels with inlet ports on the top surface and exit ports on the bottom surface and a first alignment means;

a vacuum plate having an inner and an outer surface wherein the outer surface has a vacuum fitting defining an area on the outer surface, with a plurality of vacuum ports from the inner to outer surface within the area defined by the vacuum fitting, said vacuum plate having a second alignment means;

a slide defining an opening which is covered by a porous filter membrane and further having a third alignment means;

wherein the block and the vacuum plate have spacing means providing space for removably inserting the slide between the block and the vacuum plate and wherein the first, second, and third alignment means align the block, vacuum plate, and slide such that the exit ports of the block, porous filter membrane, and vacuum ports are aligned so that when a vacuum is applied through the vacuum fitting, liquids in the block channels separately flow through the exit ports, through the porous filter membrane, and through the vacuum ports without liquids from one channel mixing with liquids from other channels on the porous filter membrane and wherein analyte or analyte complex in the filtered liquid are fixed on the porous filter membrane in a predetermined location,

said slide reading assembly comprising;

a housing with a top, bottom and inner and outer side wall sections wherein the inner side wall section has a window with a photoresponsive electrode mounted above the window on the inside of the inner side wall section so that light from an external source can pass into and be absorbed within the photoresponsive electrode;

the top section of the housing having an opening for receiving a slide to be analyzed wherein the slide has a porous filter membrane with analyte to be determined on predetermined locations on the porous filter membrane, said housing having means for aligning the predetermined locations on the porous filter membrane on the inner surface of the photoresponsive electrode opposite the window in the housing which allow light to pass to a photoresponsive electrode;

a resilient plunger mounted in the outer side wall surface of the housing opposite the photoresponsive electrode, the plunger having a stem pad such that when the plunger stem is pushed inwardly, by an operatively associated stepping motor, into the housing the pad compresses the porous membrane against the inner surface of the photoresponsive electrode;

a liquid chamber within the housing with exit and entrance ports for liquids in the top section of the housing and wherein the inner surface of the photoresponsive electrode is within the liquid chamber and the porous filter membrane is aligned above the inner surface of the photoresponsive electrode in the liquid chamber;

an intensity-modulated light source for independently irradiating the photoresponsive electrode through the window in the housing on each area of the photoresponsive electrode opposite the area of the porous filter having a predetermined location of filtered that or that complex; and

an electrical means for measuring the potential change of the surface of the photoresponsive electrode when the photoresponsive electrode is exposed to an intensity-modulated beam of light through the window in the housing and a chemical reaction is occurring between the filtered that or that complex on the porous filter membrane and a reagent in the liquid in the liquid chamber, the electrical means including a counter electrode, and an operational amplifier.

11. In combination, a filtering assembly and a slide reading assembly, said filtering assembly comprising in combination:

a block with a top and bottom surface, said block having a plurality of channels with inlet ports on the top surface and exit ports on the bottom surface and a first alignment means;

a vacuum plate having an inner and outer surface wherein the outer surface has a vacuum fitting defining an area on the outer surface, with a plurality of vacuum ports from the inner to outer surface within the area defined by the vacuum fitting, said vacuum plate having a second alignment means;

a slide having a front end and sides, the slide defining an opening which is covered by a porous filter membrane and further having a third alignment means;

wherein the block and the vacuum plate have spacing means providing space for removably inserting the slide between the block and the vacuum plate and wherein the first, second, and third alignment means align the block, vacuum plate, and slide such that the exit ports of the block, porous filter membrane, and vacuum ports are aligned so that when a vacuum is applied through the vacuum fitting, liquids in the block channels separately flow through the exit ports, through the porous filter membrane, and through the vacuum ports without liquids from one channel mixing with liquids from other channels on the porous filter membrane and wherein analyte or analyte complex in the filtered liquid filtered through the membrane are fixed on the porous filter membrane in predetermined locations,

said third alignment means providing additionally for positioning the slide in the slide reading assembly so that detection will occur at the same predetermined locations on the porous membrane, and

said slide reading assembly comprising a housing with a top, bottom and inner and outer side wall sections, said inner side wall section having an electrode mounted thereon, the top section of the housing having an opening for receiving the slide and the housing having a fourth alignment means for aligning the predetermined locations on the porous membrane to corresponding predetermined locations on the surface of the electrode.

12. A filter assembly according to claim 11, wherein the first alignment means is a hole in the bottom surface of the block;

the second alignment means is a peg in the vacuum plate that is received by the hole;

the third alignment means is a notch in the front end of the slide, which engages the peg; and

the top surface of the vacuum plate has a depression that conforms to the shape of the sides of the slide.

13. In combination, one or more filtering assemblies, each comprising a block with a top and bottom surface, said block having a plurality of channels with inlet ports on the top surface and exit ports on the bottom surface and a fist alignment means;

a vacuum plate having an inner and outer surface wherein the outer surface has a vacuum fitting defining an area on the outer surface, with a plurality of vacuum ports from the inner to outer surface within the area defined by the vacuum fitting, said vacuum plate having a second alignment means;

a slide having a front end and sides, the slide defining an opening which is covered by a porous filter membrane and further having a third alignment means;

wherein the block and the vacuum plate have spacing means providing space for removably inserting the slide between the block and the vacuum plate and wherein the first, second, and third alignment means align the block, vacuum plate, and slide such that the exit ports of the block, porous filter membrane and vacuum ports are aligned so that when a vacuum is applied through the vacuum fitting, liquids in the block channels separately flow through the exit ports, through the porous filter membrane, and through the vacuum ports without liquids from one channel mixing with liquids from other channels on the porous filter membrane and wherein analyte or analyte complex in the liquid filtered through the membrane are fixed on the porous filter membrane in predetermined locations;

a slide reading assembly cooperating with the filtering assembly, said slide reading assembly comprising a housing with a top, bottom and inner and outer side walls, said inner side wall having an electrode mounted thereon, the housing including a top section having an opening for receiving the slide, said slide being positioned so that detection will occur at the same predetermined locations on the porous membrane, and

said housing having a fourth alignment means for aligning the predetermined locations on the porous membrane to corresponding predetermined locations on the surface of the electrode.

14. The combination of claim 13 wherein the third alignment means provides additionally for positioning the slide in the slide reading assembly so that detection will occur at the same predetermined locations on the porous membrane.

15. In combination, a filtering assembly comprising a block with top and bottom surface, said block having a plurality of channels with inlet ports on the top surface and exit ports on the bottom surface and a first alignment means;

a vacuum plate having an inner and outer surface wherein the outer surface has a vacuum fitting defining an area on the outer surface, with a plurality of vacuum ports from the inner to outer surface within the area defined by the vacuum fitting, said vacuum plate having a second alignment means;

a slide having a front end and sides, the slide defining an opening which is covered by a porous filter membrane and further having a third alignment means;

wherein the block and the vacuum plate have spacing means providing space for removably inserting the slide between the block and the vacuum plate and wherein the first, second, and third alignment means align the block, vacuum plate, and slide such that the exit ports are aligned so that when a vacuum is applied through the vacuum fitting, liquids in the block channels separately flow through the exit ports, through the porous filter membrane, and through the vacuum ports without liquids from one channel mixing with liquids from other channels on the porous filter membrane and wherein analyte or analyte complex in the liquid filtered through the membrane are fixed on the porous filter membrane in predetermined locations, and a slide reading assembly comprising a housing with a top, bottom, and inner and outer sidewall sections wherein the inner side wall section has a window with an electrode mounted thereon;

the housing having a top section having an opening for receiving said slide to be analyzed; and

wherein the third alignment means provides additionally for positioning the slide in said slide reading assembly so that detection will occur at the same predetermined locations on the porous membrane a photoresponsive electrode having an inner surface, means mounted in the outer side wall surface of the housing for compressing the porous membrane against the inner surface of the photoresponsive electrode;

a liquid chamber within the housing with exit and entrance ports for liquids in the top section of the housing and wherein the inner surface of the photoresponsive electrode is within the liquid chamber and the porous membrane is aligned above the inner surface of the photoresponsive electrode in the liquid chamber a window on the housing on each side of the photoresponsive device;

an intensity-modulated light source for independently irradiating the photoresponsive electrode through said window in the housing on each side of the photoresponsive electrode opposite the area of the porous membrane and an electrical means for measuring a potential change of the surface of the photoresponsive electrode when the photoresponsive electrode is exposed to an intensity-modulated beam of light through the window in the housing and a chemical reaction is occurring between the filtered analyte or analyte complex on the porous filter membrane and a reagent in the liquid in the liquid chamber.