Microorganism concentration process
A process for capturing or concentrating microorganisms for detection or assay comprises (a) providing a particulate concentration agent that comprises gamma-FeO(OH); (b) providing a fluid sample comprising at least one microorganism strain; and (c) contacting the concentration agent with the sample such that at least a portion of the concentration agent is dispersed in the sample and at least a portion of the at least one microorganism strain is bound to or captured by the concentration agent.
1. A process comprising:
(a) providing a particulate concentration agent that consists essentially of gamma-FeO(OH) that comprises microparticle agglomerates comprising acicular crystallites that are less than 1 micrometer in largest dimension, wherein the microparticle agglomerates have particle sizes in the range of 3 micrometers to 100 micrometers in largest dimension;
(b) providing a fluid sample comprising at least one microorganism strain selected from strains of bacteria, yeasts, bacterial endospores, bacteriophages, and combinations thereof;
(c) contacting said concentration agent with said sample such that at least a portion of said concentration agent is dispersed in said sample and at least a portion of said at least one microorganism strain is bound to or captured by said concentration agent to provide a microorganism-bound concentration agent;
(d) segregating the resulting microorganism-bound concentration agent, wherein said segregating is effected by gravitational settling of the microorganism-bound concentration agent, wherein the gravitational settling is achieved over a time period of about 5 minutes to about 30 minutes; and
(e) detecting the presence of at least one viable bound microorganism.
2. The process of claim 1 , wherein said microorganism strain is selected from strains of bacteria, yeasts, and combinations thereof.
3. The process of claim 2 , wherein said microorganism strain is selected from strains of bacteria and combinations thereof.
4. The process of claim 1 , wherein said microorganism strain is selected from strains of gram-negative bacteria and combinations thereof.
5. The process of claim 1 , wherein said contacting is carried out by mixing said concentration agent and said sample.
6. The process of claim 1 , wherein said detecting is carried out by a method selected from culture-based methods, microscopy and other imaging methods, genetic detection methods, immunologic detection methods, bioluminescence-based detection methods, and combinations thereof.
7. The process of claim 1 , wherein said process further comprises separating the resulting segregated concentration agent from said sample.
8. A kit comprising (a) a particulate concentration agent that consists essentially of gamma-FeO(OH) that comprises microparticle agglomerates comprising acicular crystallites that are less than 1 micrometer in largest dimension, wherein the microparticle agglomerates have particle sizes in the range of 3 to 100 micrometers in largest dimension, and wherein the microparticle agglomerates have particles sizes in a range from 3 micrometers to 100 micrometers in largest dimension; (b) a testing container; (c) instructions for using said concentration agent in carrying out the process of claim 1 ; and (d) at least one of a genetic detection assay component, a bioluminescence detection assay component, a microorganism count plate, an antibody, a polypeptide, an aptamer, a fluorescent dye, or an enzyme.
9. The method of claim 1 , wherein the contacting is carried out for a period of about 15 seconds to about 5 minutes.