Method and device for concentrating selected groups of microorganisms
A method and device are described to concentrate target organisms from a mixture of organisms. Beads ( 1 ) made of material such as nylon, polystyrene or glass are coated with antibodies of specific microorganisms. The beads ( 1 ) are contained in an enclosure ( 2 ) surrounded by grid material ( 4 ). The pore size of the grid is smaller than the size of the beads, to assure that the beads stay within the grid material and larger than the size of the microorganisms to allow the interaction of the microorganisms with the beads. A rod ( 5 ) is attached to the upper part of the enclosure ( 2 ) allowing the agitation of the device inside he growth medium containing the target organisms.
1. A method of separating target microorganisms from a suspension, comprising:
immersing a plurality of beads coated with at least one antibody material into the suspension, said beads being contained within the interior space of an enclosure having a pore size smaller than the size of said beads and larger than the size of the microorganisms,
suspending the enclosure in the suspension thereby allowing the capture of the target microorganisms by said beads; and
washing said beads to remove organisms not bound to said beads, thereby separating target microorganisms from the suspension.
2. The method of claim 1 wherein at least one detergent is applied in said washing.
3. The method of claim 1 further comprising agitation of said enclosure holding said beads in the suspension.
4. The method of claim 1 wherein the time period of agitation is at least 30 minutes.
5. The method of claim 1 wherein the time period of agitation extends for several hours.
6. The method of claim 1 including the addition of at least one detergent to the suspension to decrease absorption of non-specifically bound cells.
7. The method of claim 1 including the subsequent step of immersing the enclosure and beads in new growth broth.
8. The method of claim 7 including the addition of an indicator material to the new growth broth.
9. The method of claim 1 including the subsequent step of separating the beads from the enclosure followed by at least one test to reveal the microorganisms of interest.
10. The method of claim 1 wherein said enclosure further comprises means attached to the enclosure for moving the enclosure in the suspension and for subsequent removal of the enclosure from the suspension.
11. The method of claim 10 wherein said means attached to the enclosure for moving the enclosure in the suspension and for subsequent removal of the enclosure from the suspension is attached to an upper part of the enclosure.
12. The method of claim 1 wherein said enclosure is made of a grid material.
13. The method of claim 3 wherein said enclosure holding said beads in the suspension is agitated with a rod or string attached to the enclosure.
14. The method of claim 1 wherein said enclosure is in the shape of a teabag.
15. The method of claim 1 wherein said enclosure is cylindrical.