Low-volume coagulation assay

Abstract

Compositions and methods for measuring coagulation parameters using very small volumes of blood are provided. Advantageously, the methods described herein can be performed from a single drop of blood (about 20 μL) while generally leaving enough sample to perform other measurements, optionally in a multiplexed format. The methods and devices do not require a skilled operator and can be performed at the point of service, which can be an important feature for managing blood coagulation disorders and treatments thereof.

1 . A method for measuring coagulation time of a blood sample of a subject, comprising:
 (a) initiating a coagulation reaction of the blood sample of the subject;   (b) obtaining a set of more than one image of said coagulation reaction; and   (c) analyzing said set of images to measure the coagulation time of said blood sample.   
     
     
         2 . The method of  claim 1 ,
 wherein the amount of time for carrying out steps (a) to (c) is less than or about 1 hour.   
     
     
         3 .- 4 . (canceled) 
     
     
         5 . The method of  claim 1 , wherein an individual image of said set of images is pixilated and comprises at least 10,000 pixels. 
     
     
         6 . The method of  claim 1 , further comprising diluting said blood sample such that the coagulation time of the blood sample after dilution is between about 1 minute and about 10 minutes. 
     
     
         7 . The method of  claim 6 , further comprising adding fibrinogen to the coagulation reaction. 
     
     
         8 .- 9 . (canceled) 
     
     
         10 . The method of  claim 1 , wherein said blood sample is obtained via a non-venous route. 
     
     
         11 . The method of  claim 1 , wherein said images are light scattering images of the coagulation reaction. 
     
     
         12 . The method of  claim 1 , wherein the coagulation time is measured based on a transition of the intensity of said scattered light. 
     
     
         13 . The method of  claim 1 , further comprising adding a plurality of beads to said blood sample prior to obtaining the set of images. 
     
     
         14 . The method of  claim 13 , wherein said plurality of beads comprise beads of at least two different sizes. 
     
     
         15 .- 17 . (canceled) 
     
     
         18 . The method of  claim 13 , wherein said step of analyzing said set of images comprises locating a time point when said beads become substantially motionless. 
     
     
         19 . The method of  claim 13 , wherein said step of analyzing said set of images comprises locating the time point when a transition of the mobility of said beads occurs. 
     
     
         20 .- 22 . (canceled) 
     
     
         23 . The method of  claim 13 , wherein said beads are labeled. 
     
     
         24 . The method of  claim 23 , wherein said beads are labeled with a fluorescent label. 
     
     
         25 - 53 . (canceled)