Non-centrifugation method for immunoassay of materials

Claim 1

A method for carrying out an immunoassay with a mass transport operation of one or more components from one phase to another phase, and with a subsequent separation of an upper liquid phase, wherein the mass transport and separation are carried out in the same device, said method being carried out in a device comprising a vertical mixing reservoir; a mixer-separator snuggly fitted into said reservoir for sliding movement therein and having at least one channel passing axially therethrough, said mixer-separator including at its lower end a barrier which is selectively permeable to the upper liquid phase in said mixing reservoir and at its upper end a container into which opens said at least one channel for accumulating the separated liquid from said upper liquid phase from the mixing reservoir forced through said barrier and said channel as said mixer-separator is pushed into said mixing reservoir; a sealing element surrounding said mixer-separator at a preselected distance above the lower end of said mixer-separator and above said barrier; and means defining a space positioned in the axial direction between said barrier and said sealing element, for providing a gas cushion for decreasing the pressure exerted on said barrier in response to pushing of said mixer-separator into said mixing reservoir, the configuration of said space and the gas cushion being selected so as to force back into said mixing reservoir any of the upper liquid phase which has crept up along the inner wall of the mixing reservoir above the lower end of the mixer-separator, whereby substantially quantitative separation of the upper liquid phase can be accomplished, said method comprising the steps of: (a) arranging a plurality of the mixing reservoirs in a rack designed to hold a number of said mixing reservoirs; (b) introducing a reagent and analyte into each of said mixing reservoirs; (c) capping each of said mixing reservoirs with one of said mixer-separator means; (d) allowing the reagents and analytes to incubate for a required period of time in the mixing reservoirs capped with the mixer-separator means; (e) placing the rack carrying the capped devices with the incubated reagents and analytes into a press-device designed to perform at a controlled rate a downward movement whereby the mixer-separator means are pushed downwardly into the mixing reservoirs at a chosen rate and for a preselected distance sufficient to complete the desired mass-transport and separation operations; (f) operating the downward movement of said press-device at the preselected rate and distance sufficient to separate the phase which passes through said barrier from the phase which cannot pass through said barrier; (g) removing the rack upon the disengagement of the press-device; and (h) placing the separator devices into the desired analytical instrument for a quantitative or qualitative measurement of either one, or both, of the separated phases.

Claim 2

A method for carrying out an immunoassay with a mass transport operation of one or more components from one phase to another phase, and with a subsequent separation of an upper liquid phase, wherein the mass transport and separation are carried out in the same device, said method being carried out in a device comprising a vertical mixing reservoir; a mixer-separator snuggly fitted into said reservoir for sliding movement therein and having at least one channel passing axially therethrough, said mixer-separator including at its lower end a barrier which is selectively permeable to the upper liquid phase in said mixing reservoir and at its upper end a container into which opens said at least one channel for accumulating the separated liquid from said upper liquid phase from the mixing reservoir forced through said barrier and said channel as said mixer-separator is pushed into said mixing reservoir; a sealing element surrounding said mixer-separator at a preselected distance above the lower end of said mixer-separator and above said barrier; and means defining a space positioned in the axial direction between said barrier and said sealing element, for providing a gas cushion for decreasing the pressure exerted on said barrier in response to pushing of said mixer-separator into said mixing reservoir, the configuration of said space and the gas cushion being selected so as to force back into said mixing reservoir any of the upper liquid phase which has crept up along the inner wall of the mixing reservoir above the lower end of the mixer-separator, whereby substantially quantitative separation of the upper liquid phase can be accomplished, said method comprising the steps of: (a) arranging a plurality of the mixing reservoirs in a rack designed to hold a number of said mixing reservoirs; (b) introducing a reagent and analyte into each of said mixing reservoirs; (c) capping each of said mixing reservoirs with one of said mixer-separator means; (d) allowing the reagents and analytes to incubate for a required period of time in the mixing reservoirs capped with the mixer-separator means; (e) placing the rack carrying the capped devices with the incubated reagents and analytes into a press-device designed to perform at a controlled rate a downward movement whereby the mixer-separator means are pushed downwardly into the mixing reservoirs at a chosen rate and for a preselected distance sufficient to complete the desired mass-transport and separation operations; (f) operating the downward movement of said press-device at the preselected rate and distance sufficient to separate the phase which passes through said barrier from the phase which cannot pass through said barrier; (g) removing the rack upon the disengagement of the press-device; and (h) placing the separator devices into the desired analytical instrument for a quantitative or qualitative measurement of either one, or both, of the separated phases.