Recycling immunoaffinity chromatography for multiple analyte analysis in biological samples

The ability to isolate and measure multiple complex analytes in a single biological sample holds great potential in many biomedical fields, especially immunology and diagnostic clinical chemistry. We have developed a procedure involving recycling immunoaffinity chromatography for the simultaneous measurement of a number of analytes in a single sample. The procedure is based on the passage of a fluorochrome-labelled sample through a battery of small immunoaffinity columns, each column extracting a single analyte. Detection is achieved by acid elution of the bound analytes and laser-induced fluorescence. We have applied this system to a number of different biological fluids and found that it is capable of reliably isolating and measuring up to ten different cytokines in a 25-microl sample of human body fluid.