Analytical test device and method for use in medical diagnoses

An analytical test device suitable for determining the presence of at least one analyte contained in a liquid sample while permitting rapid and efficient flow of the sample through at least one defined pathway in which reactions determinative of the analyte take place, said device comprising:

• a top layer having an upper surface formed with a through hole for the addition of the sample, said through hole being in registry with a sample delivery channel formed in the upper surface of the top layer, said sample delivery channel in operative communication with a sample circulation channel closed at its terminal ends and formed with inner and outer walls to define a pathway for the sample in the lower surface of the top layer, the inner walls of the circulation channel defining an indent in the lower surface of the top layer;
• a bottom layer attached to the top layer, said bottom layer and top layer holding a dry porous carrier therebetween, said dry porous carrier having a fluid pathway;
• said fluid pathway of said dry porous carrier layer configured to contain at least one detection zone having a border in operative communication with a segment of the sample circulation channel and an opposite end in operative communication with a capture zone channel having an entrance end and a closed terminal end thereby to provide a conduit through which the liquid sample may flow by capillary action from the sample circulation channel from a plurality of different directions onto the porous carrier and to the entrance of the capture zone channel, into the capture zone channel, to the terminal end of the capture zone channel;
• and
• the delivery channel, circulation channel, detection zone and capture zone channel forming a defined pathway through which the liquid sample flows from the through hole to the terminal end of the capture channel;
• there being immobilized reagent in the capture zone channel which will react with said analyte to form a detectable product.

A method for determining the presence of at least one analyte contained in a liquid sample comprising the steps of:

• i) providing an analytical test device suitable for determining the presence of at least one analyte contained in a low volume of a liquid biological sample while permitting rapid and efficient flow of the sample through at least one defined pathway which reactions determinative of the analyte take place, said device comprising:
• a) a top layer having an upper surface formed with a through hole for the addition of the sample, said through hole being in registry with a sample delivery channel formed in the upper surface of the top layer, said sample delivery channel in operative communication with a sample circulation channel closed at its terminal ends and formed with inner and outer walls to define a pathway for the sample in the lower surface of the top layer, the inner walls of the circulation channel defining an indent in the lower surface of the top layer;
• b) a bottom layer attached to the top layer, said bottom layer and top layer holding a dry porous carrier therebetween, said dry porous carrier having a fluid pathway;
• c) said fluid pathway of said dry porous carrier layer configured to contain at least one detection zone having a border in operative communication with a segment of the sample circulation channel and an opposite end in operative communication with a capture zone channel having an entrance end and a closed terminal end thereby to provide a conduit through which the liquid sample may flow by capillary action from the sample circulation channel from a plurality of different directions onto the porous carrier and to the entrance of the capture zone channel, into the capture zone channel, to the terminal end of the capture zone channel, the delivery channel, circulation channel, detection zone and capture zone channel forming a defined pathway through which the liquid sample flows from the through hole to the terminal end of the capture channel;
• there being immobilized reagent in the capture zone channel which will react with said analyte to form a detectable product;
• ii) applying a quantity of said fluid sample to said detection zone;
• iii) permitting a sufficient period of time to elapse for the fluid sample to flow from the detection zone from said plurality of different directions to the capture zone channel and any said analyte therein to form a detectable reaction product at said capture zone;
• and
• iv) identifying the presence of said at least one analyte in said fluid sample by detecting any said detectable reaction product at said capture zone.