Multi-purpose electrophoresis apparatus

• US 5,449,446 A
• Filed: 03/09/1994
• Issued: 09/12/1995
• Est. Priority Date: 03/09/1994
• Status: Expired due to Fees

• Current Assignee: Kuldeep Verma, Sumeet Verma
• Original Assignee: Kuldeep Verma, Sumeet Verma
• Inventors: Verma, Sumeet, Verma, Kuldeep
• Primary Examiner(s): Niebling, John
• Assistant Examiner(s): STARSIAK, JOHN S
• Application Number:
  US08/208,604
• Time in Patent Office: 552 Days
• Field of Search: 204/299 R, 204/301, 204/182.8
• US Class Current: 204/612
• CPC Class Codes: G01N 27/44721 by optical means
• CPC Class Codes: G01N 27/44739 Collecting the separated zones, e.g. blotting to a membrane or punching of gel spots

Abstract

The invention disclosed herein comprises a laboratory electrophoresis apparatus which overcomes many drawbacks of the previously known apparatus by combining a number of operations in the same unit, thereby eliminating the need for moving a gel between analytic jobs. The apparatus of the invention has a gel casting platform permanently mounted in a buffer container with retractable dams on two opposite sides to retain the gel casting liquid prior to solidification. The gel remains in place on the platform and the dams are retracted for filling the buffer container and a vertical electric field is applied to compact the sample placed in the sample wells to the bottom. The electrophoresis in a horizontal direction is performed and may be observed by means of an included UV radiation source capable of causing the ethidium bromide treated molecular samples to emit visible light, which is observable through a UV opaque safety cover. A viewing hood including a UV cross-linking source may be substituted for viewing, especially during blotting or eluting operations, for which the gel is not moved from its casting platform. To do blotting, either a complete transfer membrane or a partial, single band membrane with a novel holder is used. A further operation is performed by the replacement of the viewing hood with a photography hood for the placement of a camera, capable of either UV or visible light photography. By this combination of features, the multi-purpose apparatus of the invention permits all necessary molecular analytic operations without the movement of the gel, thus improving the efficiency and reliability of results.

Claims

1. A multi-purpose apparatus for separation, transfer, visualization and recording of molecular samples in a gel, said apparatus comprising:

(a) an open topped container having a planar floor;

(b) a substantially rectangular planar gel casting platform mounted on a similarly sized porous spacer so that an upper surface of said platform resides horizontally within said container at a selected distance above said floor;

(c) means positioned adjacent said platform in a manner to be moveable between a liquid retaining position for retaining a liquid on said platform which will harden to a gel and a retracted position;

(d) a comb mountable within said container so as to reside proximately above said platform and adapted for forming a plurality of sample receiving wells into an upper surface of said gel;

(e) means mounted within said container to establish a first electric field oriented parallel to and straddling said gel for separating said molecular samples into discrete bands;

(f) a membrane superimposed upon said cast gel for reception of said bands transferred from said gel;

(g) a porous net superimposed upon said membrane;

(h) means mounted within said container so as to establish an alternate electric field vertically straddling said gel so as to cause the molecular sample to migrate vertically;

(i) an UV radiation source mounted within said container in a position below said platform; and

(j) a power source connectable to said electric field establishing means through a normally open switch mounted to said container.

2. A multi-purpose apparatus as recited in claim 1, further comprising a UV opaque cover attachable to said container so as to be moveable between an open and a closed position, and adapted to block UV radiation so as to allow safe viewing of said gel during UV irradiation and further adapted to cause said normally open switch to close.

3. A multi-purpose apparatus as recited in ,claim 1, further comprising a viewing hood removeably mountable on said container in a position over said open top, said hood being formed of UV and visible light blocking material and having a UV blocking, visible light transparent window formed therethrough for viewing of said gel during UV irradiation.

4. A multi-purpose apparatus as recited in claim 3, further comprising an opening formed in a side of said hood and adapted for accessing materials confined beneath said viewing hood when said viewing hood is mounted upon said container and a service door hingedly attached adjacent said opening such that said door is moveable between an open and a closed position of said opening.

5. A multi-purpose apparatus as recited in claim 3, wherein said viewing hood is adapted so as to close said normally open switch on said container.

6. A multi-purpose apparatus as recited in claim 3, further comprising a cross-linking UV radiation source mounted within said viewing hood and adapted for UV cross-linking of a molecular sample to said membrane and a means to energize and de-energize said cross-linking UV radiation source and an UV blocking material secured into said viewing hood in a position to enclose said UV radiation source.

7. A multi-purpose apparatus as recited in claim 1, wherein said container is made from a material capable of blocking visible light.

8. A multi-purpose apparatus as recited in claim 1, further comprising a pair of perforate walls extending vertically from said floor of said container in parallel, spaced apart orientation and forming a channel capable of receiving said spacer within said container.

9. A multi-purpose apparatus as recited in claim 1, wherein said means to retain said liquid upon said platform comprise a pair of dams, respectively vertically slidably attached to said vertically extending walls in a position so as to be moveable between an upper liquid retaining position and a lower retracted position.

10. A multi-purpose apparatus as recited in claim 1, further comprising a first porous membrane holder adapted to be operable in a horizontal orientation and including a plurality of piercing legs for insertion into said gel and a cup mounted directly above said held membrane, said membrane holder insertable into a microfuge tube for eluting a selected sample band from said membrane.

11. A multi-purpose apparatus as recited in claim 1, further comprising a second porous membrane holder having a pair of hingeably connected sides and adapted to be operable in a vertical orientation.

12. A multi-purpose apparatus as recited in claim 1, further comprising a membrane retainer insertable into said gel directly above a selected sample band for containing said gel and said membrane firmly between said gel and said retainer.

13. A multi-purpose apparatus as recited in claim 1, further comprising a plurality of protrusions formed integral with inner surfaces of said container above said gel casting platform for engaging and securing the position of said gel.

14. A multipurpose apparatus as recited in claim 1, wherein said platform is porous and a pair of opposed walls adjacent said platform are formed to slope inwardly so as to be closer together at their top edges than they are at their bottom edges so as to secure the position of said gel.

15. A multi-purpose apparatus as recited in claim 1, further comprising a gel partitioner mounted within said container and adapted to divide said gel along a line parallel to the direction of said first electrical field.

16. A multi-purpose apparatus as recited in claim 1, further comprising a camera hood mountable on said container and configured to receive a camera for photography of said gel located on said platform.

17. A multi-purpose apparatus as recited in claim 1, further comprising a viewing window formed from UV filtering material penetrating through a wall of said container.

18. A multi-purpose apparatus as recited in claim 16, further comprising a door moveable between a closed position in which said door covers the said viewing window and an open position in which said viewing window is uncovered.

19. A multi-purpose apparatus as recited in claim 1, further comprising a movable porous spacer box having porous upper and lower plates with interconnecting porous side walls adapted for mounting within said container.

20. A multi-purpose apparatus as recited in claim 1, wherein said container has an intake and an outlet for a liquid and further comprising liquid supply means adapted for maintaining said liquid at a selected level in said container.

21. A multi-purpose apparatus as recited in claim 1, wherein said gel casting platform is porous, is sealed peripherally to said container and spaced above said floor, and further comprising a vacuum source connected so as to be able to apply a vacuum beneath said gel casting platform so as to transfer a molecular sample from said gel to a membrane positioned beneath said gel.

22. A multi-purpose apparatus as recited in claim 1, further comprising means within said container for mechanically circulating a liquid in said container.

23. A multi-purpose apparatus for separation, transfer, visualization and recording of molecular samples in a gel, said apparatus comprising:

(a) an open topped container having a planar floor;

(b) a substantially rectangular planar gel ,casting platform mounted on a similarly sized porous spacer so that an upper surface of said platform resides horizontally within said container at a selected distance above said floor;

(c) means positioned adjacent said platform for retaining a liquid on said platform which will harden to a gel;

(d) a comb mountable within said container so as to reside proximately above said platform and adapted for forming a plurality of sample receiving wells into an upper surface of said gel;

(e) means mounted within said container to establish a first electric field oriented parallel to and straddling said gel for separating said molecular samples into discrete bands;

(f) a membrane superimposed upon said cast gel for reception of said bands transferred from said gel;

(g) a porous net superimposed upon said membrane;

(h) means mounted within said container so as to establish an alternate electric field vertically straddling said gel so as to cause the molecular sample to migrate vertically;

(i) an UV radiation source mounted within said container in a position below said platform; and

(j) a power source connectable to said electric field establishing means through a normally open switch mounted to said container.

24. A multi-purpose apparatus for separation, transfer, visualization and recording of molecular samples in a gel, said apparatus comprising:

(a) an open topped container having a planar floor;

(b) a substantially rectangular planar gel ,casting platform mounted on a similarly sized porous spacer so that an upper surface of said platform resides horizontally within said container at a selected distance above said floor;

(c) means positioned adjacent said platform in a manner to be moveable between a liquid retaining position for retaining a liquid on said platform which will harden to a gel;

(d) a comb mountable within said container so as to reside proximately above said platform and adapted for forming a plurality of sample receiving wells into an upper surface of said gel;

(e) means mounted within said container to establish a first electric field oriented parallel to and straddling said gel for separating said molecular samples into discrete bands;

(f) a membrane superimposed upon said cast gel for reception of said bands transferred from said gel;

(g) a porous net superimposed upon said membrane;

(h) means mounted within said container so as to establish an alternate electric field vertically straddling said gel so as to cause the molecular sample to migrate vertically;

(i) a power source connectable to said electric field establishing means through a normally open switch mounted to said container; and

(j) a viewing hood removeably mountable on said container in a position over said open top, said hood being formed of UV and visible light blocking material and having a UV blocking, visible light transparent window formed therethrough for viewing of said gel during UV irradiation and including means to generate UV radiation for viewing said molecular samples and for cross-linking said molecular samples.