Chemical Assays

Abstract

An assay device in which to carry out a fluid-phase chemical assay, comprising means for supporting a test substrate, a sample chamber for receiving a fluid sample and at least one fluid control device for controlling the movement of fluid into and/or out of the sample chamber, wherein the fluid control device comprises a fluid outlet chamber in fluid communication with the sample chamber, and a displaceable flexible diaphragm the displacement of which alters the volume of the outlet chamber so as to allow and/or restrict fluid flow between the outlet and sample chambers. The invention also provides assay apparatus incorporating such a device, an assay station for use as part of such apparatus, a fluid control unit for use as part of the assay device and a method of conducting an assay which may involve the use of such apparatus and devices.

1 . A method of conducting a plurality of fluid-phase chemical assays, which involves supporting a plurality of test substrates in a corresponding number of assay devices, and conducting a fluid-phase chemical assay in each device, simultaneously or sequentially. 
     
     
         2 . A method of conducting a plurality of fluid-phase chemical assays according to  claim 1  further comprising:
 placing fluid samples in contact with said test substrates via a plurality of sample chambers, and   controlling the movement of fluid into and/or out of said plurality of sample chambers using at least one fluid control chamber per assay device.   
     
     
         3 . A method of conducting a plurality of fluid-phase chemical assays according to  claim 2  further comprising:
 inducing fluid movement within said plurality of sample chambers via a fluid agitation device,   varying the pressure of the fluids supplied to said sample chambers, and   controlling the volume of said plurality of said sample chambers via a displaceable diaphragm.   
     
     
         4 . A method of conducting a plurality of fluid-phase chemical assays according to  claim 3  further comprising:
 incorporating two or more of said fluid agitation devices to reciprocally move fluid back and forth through the plurality of said sample chambers.   
     
     
         5 . A method of conducting a plurality of fluid-phase chemical assays according to  claim 4  further comprising:
 monitoring fluid flow via a flow rate monitoring device, and   controlling the temperature in said plurality of sample chambers.   
     
     
         6 . A method of conducting a plurality of fluid-phase chemical assays according to  claim 5  further comprising:
 mixing the fluids in a fluid mixing device to be directed to said plurality of assay devices.   
     
     
         7 . A method of conducting a plurality of fluid-phase chemical assays according to  claim 1  further comprising:
 immobilizing at least one probe species on said plurality of test substrates,   binding said probe species to said target test substrate,   reacting said probe species with said plurality of test substrates, and   detecting said bound pair using conventional techniques such as fluorescence, chemiluminescence, and colored dyes.   
     
     
         8 . A method of conducting a fluid-phase chemical assay which comprises:
 supporting a test substrate in an assay device,   controlling the movement of fluid in a sample chamber in contact with said test substrate,   incorporating at least one fluid control device which comprises a fluid outlet chamber in fluid communication with said sample chamber, and a displaceable flexible diaphragm,   displacing said diaphragm to alter the volume of said fluid outlet chamber so as to control fluid flow between said fluid outlet chamber and said sample chamber.