Whole blood analyses and diffusion apparatus therefor
AssigneeTechnicon Instruments Corporation
InventorBruce J. Oberhardt
Life of this patent
Estimating the term…
Abstract
Methods and apparatuses are featured for analyzing whole blood samples by diffusion techniques in porous media. A fluid component of the whole blood is diffused into a thin-film porous medium of a given predetermined volume. Hematocrit dependent errors in diffusion time do not pose a problem in obtaining a precise aliquot of the fluid component of the whole blood due to rapid diffusion and saturation of the fluid component into the porous medium. In another embodiment, diffusion switches or valves allow for precise aliquots in porous media by control of the diffusion and/or reaction of sample analyte with reagents.
Claims31
An apparatus for analyzing a whole blood sample, comprising:
- a first-thin film porous medium of a given predetermined volume for contact with said whole blood sample to be analyzed, a fluid component of said sample diffusing into said first porous medium;
- a second porous medium containing at least one reagent therein;
- a fluid barrier interposed between said first and second porous media to isolate said reagent and said fluid component;
- means for contacting said first porous medium with said second porous medium, to allow cross-diffusion therebetween, said contacting means including means for displacing said fluid barrier from between at least portions of opposing surfaces of said first and second media and cause said opposing surfaces to contact;
- and
- means to measure a reaction between said reagent and said fluid component in either of said first or second media.
An apparatus for analyzing a fluid sample for an analyte, comprising:
- a first porous medium for containing said analyte of said fluid sample;
- a second porous medium containing at least one reagent for reaction with said analyte of said fluid sample;
- a liquid barrier disposed between said first and second media to isolate said reagent from said analyte;
- and
- means for displacing said liquid barrier from between said first medium and said second medium to allow contact therebetween, whereby said analyte and said reagent can cross diffuse and react.
A diffusion switch comprising:
- a first porous medium adapted to contain a first fluid for diffusion to a second porous medium;
- a second porous medium for receiving said first fluid when said second porous medium is in contact with said first porous medium;
- a second fluid disposed between said first porous medium and said second porous medium, said second fluid serving as a diffusion barrier between said first medium and said second medium;
- and
- means for displacing said second fluid from between said first medium and said second medium to allow contact therebetween, whereby diffusion of said first fluid can occur from said first medium to said second medium.
A diffusion switch comprising:
- a first porous medium adapted to contain a first fluid comprising a component for diffusion to a second porous medium;
- a second porous medium for receiving said component when said second porous medium is in contact with said first porous medium;
- a second fluid disposed between said first porous medium and said second porous medium, said second fluid serving as a diffusion barrier between said first medium and said second medium;
- and
- means for displacing said second fluid from between said first medium and said second medium to allow contact therebetween, whereby diffusion of said component can occur from said first medium to said second medium.
A method of performing a reaction with an analyte of a sample, comprising the steps of:
- (a) diffusing said analyte into a first porous medium;
- (b) contacting said first porous medium with a second porous medium to allow diffusion of said analyte into said second porous medium, said second porous medium having at least one first reagent for reaction with said analyte;
- and
- (c) contacting said second porous medium with a third porous medium containing at least one second reagent, said contacting of at least two of said porous media comprising the displacement of a liquid from between said two media.
Dependencies are inferred from the claim text.