Microorganism concentration process and device
A process for capturing or concentrating microorganisms for detection or assay comprises (a) providing a concentration device comprising a sintered porous polymer matrix comprising at least one concentration agent that comprises an amorphous metal silicate and that has a surface composition having a metal atom to silicon atom ratio of less than or equal to 0.5, as determined by X-ray photoelectron spectroscopy (XPS); (b) providing a sample comprising at least one microorganism strain; and (c) contacting the concentration device with the sample such that at least a portion of the at least one microorganism strain is bound to or captured by the concentration device.
1. A concentration device comprising a sintered porous polymer matrix comprising at least one concentration agent that comprises an amorphous metal silicate and that has a surface composition having a metal atom to silicon atom ratio of less than or equal to 0.5, as determined by X-ray photoelectron spectroscopy (XPS), wherein about 75 to about 99 volume percent of the amorphous metal silicate is free of sharp corners or edges, wherein said metal is magnesium.
2. The concentration device of claim 1 , wherein said sintered porous polymer matrix comprises at least one thermoplastic polymer.
3. The concentration device of claim 2 , wherein said thermoplastic polymer is selected from olefin homopolymers, olefin copolymers, copolymers of olefins and other vinyl monomers, and combinations thereof.
4. The concentration device of claim 3 , wherein said thermoplastic polymer is selected from olefin homopolymers and combinations thereof.
5. The concentration device of claim 4 , wherein said olefin homopolymer is polyethylene.
6. The concentration device of claim 5 , wherein said polyethylene comprises an ultra-high molecular weight polyethylene having a molecular weight of at least about 750,000.
7. The concentration device of claim 1 , wherein said sintered porous polymer matrix comprises at least one polymer having a particle shape comprising surface convolutions.
8. The concentration device of claim 1 , wherein said concentration device comprises a tortuous path matrix.
9. The concentration device of claim 1 , wherein said surface composition has a metal atom to silicon atom ratio of less than or equal to 0.4.
10. The concentration device of claim 1 , wherein said surface composition has a metal atom to silicon atom ratio of less than or equal to 0.3.
11. The concentration device of claim 1 , wherein said concentration agent has a negative zeta potential at a pH of 7.
12. The concentration device of claim 1 , wherein said concentration agent has a zeta potential in the range of about −9 millivolts to about −25 millivolts at a pH of 7.
13. The concentration device of claim 1 , wherein said concentration agent comprises an amorphous metal silicate in at least partially fused particulate form and having a particle size in the range of 1 micrometer to 15 micrometers.
14. The concentration device of claim 13 , wherein said concentration agent is amorphous, spheroidized magnesium silicate.
15. The concentration device of claim 1 , wherein said concentration agent is present in an amount of up to about 90 weight percent of the concentration device.
16. The concentration device of claim 1 , wherein said concentration agent is present in an amount of between about 10 weight percent and about 80 weight percent of the concentration device.
17. The concentration device of claim 1 , wherein said concentration agent comprises at least one particulate concentration agent embedded in or on the surface of the porous polymer matrix.
18. The concentration device of claim 1 , wherein said concentration agent is shaped as solid spheres.
19. The concentration device of claim 7 , wherein said at least one polymer having a particle shape comprising surface convolutions has a bulk density of 0.25-0.30 grams per cubic centimeter.
20. The concentration device of claim 1 , wherein the concentration agent has a surface area of 3.3 m 2 /g, a particle density of 2.3 g/cc, or both.