Method for quantitative analysis of body fluid constituents

A method for quantitatively analyzing a biological fluid for an analyte comprising the following steps:

• depositing a biological fluid sample in a first open reservoir of an analytical device, said first open reservoir having means for separating solids from a fluid sample, whereby solids in said biological fluid sample are substantially retained in said first open reservoir;
• drawing said biological fluid sample through a channel from said first open reservoir to a second open reservoir to fill said second open reservoir with said biological fluid sample, said second reservoir being configured so as to draw a precise predetermined volume of biological fluid sample through said channel;
• said channel including a permeable membrane having at least one reagent specific for the analyte to be determined, said reagent including a chromatic indicator immobilized in said membrane in a predetermined amount to quantify the analyte in said biological fluid, whereby analyte in said biological fluid sample reacts with said reagent to produce a color change in said channel;
• said channel being provided with calibration means related to said color change to quantify the amount of analyte present in said biological fluid sample.