Point of care sepsis assay device and method

Abstract

Disclosed is a point of care sepsis assay comprising a disposable assay cartridge with a sample inlet for a blood sample, a filter to isolate blood plasma, a source of multivalent cations to cause a turbidity change in the plasma sample and a transparent window to measure the change in turbidity and the use of said assay in the diagnosis of sepsis.

1 - 21 . (canceled) 
     
     
         22 . An assay cartridge device for detecting sepsis in blood plasma comprising a reaction chamber with a dried material containing a source of multivalent cations, where the dried material is present only on a portion of the surface of the reaction chamber, the cations causing a turbidity change in the plasma sample in the presence of sepsis, and a transparent window to measure the change in turbidity. 
     
     
         23 . A device according to  claim 22  wherein the device has an integral filter to isolate blood plasma from a blood sample. 
     
     
         24 . A device according to  claim 23  wherein the device is a disposable, single use device. 
     
     
         25 . A device according to  claim 22  wherein the multivalent cation is a divalent cation. 
     
     
         26 . A device according to  claim 25  wherein the divalent cations are metal ions. 
     
     
         27 . A device according to  claim 26  wherein the metal is calcium. 
     
     
         28 . A device according to  claim 22  wherein the device comprises a reaction chamber of defined volume wherein the volume of the reaction chamber is 10-50 microlitres (μL). 
     
     
         29 . A device according to  claim 22  wherein the window is transparent at 480 nm. 
     
     
         30 . A device according to  claim 22  wherein the optical path length of the transparent window is 0.5 mm to 10 mm. 
     
     
         31 . A device according to  claim 30  wherein the optical path length of the transparent window is 0.5 mm to 2 mm. 
     
     
         32 . A device according to  claim 25  wherein the divalent cations are present at a final concentration of greater than 10 mM in the first reaction chamber when the blood plasma has been added. 
     
     
         33 . A device according to  claim 22  wherein the cations are dried in a layer of water soluble polymer. 
     
     
         34 . A device according to  claim 33  wherein the polymer is polyethylene glycol or methyl polyethylene glycol. 
     
     
         35 . A device according to  claim 22  further comprising a reader instrument comprising a source of visible light. 
     
     
         36 . A device according to  claim 35  wherein the reader instrument comprises a measuring element for detecting the amount of light passing through the sample. 
     
     
         37 . A device according to  claim 36  wherein the measuring element is a photodiode. 
     
     
         38 . A device according to  claim 36  wherein the reader instrument comprises a pinhole between the measuring element and the sample.