Device for detecting analytes in fluid samples

Abstract

The present invention provides a device ( 100 ) for detecting the presence of an analyte in a liquid sample. The device ( 100 ) has an opening ( 115 ) for introducing the liquid sample into a first chamber ( 301 ) for collecting the liquid sample, and a second chamber ( 601 ) connected to the first chamber ( 301 ) by a passageway ( 205 ) and containing a test element. The device also has a third chamber ( 701 ) connected to the second chamber ( 601 ) by a channel and containing a movable member ( 311 ) having first and second positions. The third chamber ( 701 ) is divided by the movable member ( 311 ) into first ( 901 ) and second ( 902 ) zones, and the first zone ( 901 ) has a vent hole ( 165 ). The movable member ( 311 ) is in contact with at least one wall of the third chamber ( 701 ) to prevent gas communication between the first and second zones ( 901, 902 ).

1 . A device for detecting the presence of an analyte in a liquid sample, comprising:
 an opening for introducing the liquid sample into a first chamber for collecting the liquid sample;   a second chamber connected to the first chamber by a passageway and containing a test element;   a third chamber connected to the second chamber by a channel and containing a movable member having first and second positions, the third chamber being divided by the movable member into first and second zones and the first zone comprising a vent hole;   the movable member in contact with at least one wall of the third chamber to prevent gas communication between the first and second zones.   
     
     
         2 . The device of  claim 1  further comprising a lid for closing the opening. 
     
     
         3 . The device of  claim 1  wherein the test element is an assay card containing one or more test strips. 
     
     
         4 . The device of  claim 1  wherein the movable member is a plunger. 
     
     
         5 . The device of  claim 4  wherein the plunger contains a seal in contact with at least one wall of the third chamber to prevent gas communication between the first and second zones. 
     
     
         6 . The device of  claim 4  wherein the third chamber comprises a bottom and the vent hole is situated on the bottom of the third chamber. 
     
     
         7 . The device of  claim 4  wherein the plunger comprises a push bar extending towards the opening. 
     
     
         8 . The device of  claim 7  further comprising a lid having a surface that contacts and depresses the push bar when the lid is applied to the opening. 
     
     
         9 . The device of  claim 1  wherein the passageway has a diameter of less than 8 mm. 
     
     
         10 . The device of  claim 9  wherein the passageway has a diameter of less than about 4 mm. 
     
     
         11 . The device of  claim 1  wherein the test element comprises at least one test strip. 
     
     
         12 . A method for detecting the presence of an analyte in a liquid sample, comprising:
 introducing a liquid sample into a test device comprising
 an opening for introducing the liquid sample into a first chamber for collecting the liquid sample; 
 a second chamber connected to the first chamber by a passageway and containing a test element; 
 a third chamber connected to the second chamber by a channel and containing a movable member having first and second positions, the third chamber being divided by the movable member into first and second zones and the first zone comprising a vent hole; 
 the movable member in contact with at least one wall of the third chamber to prevent gas communication between the first and second zones; 
   causing the movable member to move from the first position to the second position and thereby causing a volume of air to be drawn from the second chamber into the third chamber, and thereby causing a volume of liquid to be drawn from the first chamber through the passageway and into the second chamber to contact the test element;   detecting the presence of the analyte in the sample.   
     
     
         13 . The method of  claim 12  wherein the test element comprises at least one test strip. 
     
     
         14 . The method of  claim 12  wherein the device further comprises a lid, and the method further comprises applying the lid to the device after introducing the sample. 
     
     
         15 . The method of  claim 14  wherein the movable member is a plunger having a push bar, and the step of applying the lid comprises contacting the lid with the push bar and depressing the push bar as the lid is applied to the device, and thereby causing the movable member to move from the first position to the second position. 
     
     
         16 . The method of  claim 15  wherein depressing the push bar and moving the movable member from the first position to the second position causes a negative air pressure gradient to form in the third chamber and the volume of air to be drawn from the second chamber into the third chamber. 
     
     
         17 . The method of  claim 16  wherein the movement of the volume of air from the second chamber to the third chamber causes a negative air pressure gradient to form in the second chamber. 
     
     
         18 . The method of  claim 17  wherein the negative air pressure gradient in the second chamber causes the fluid sample to flow from the first chamber through the passageway to the second chamber, and thereby to contact the test element. 
     
     
         19 . The method of  claim 15  wherein depressing the push bar and moving the movable member from the first position to the second position causes a volume of air to escape from the first zone through the vent hole.