Patent ID: 7951598

Claim:
A method for detecting an analyte in a liquid biological sample known or suspected to comprise red blood cells and suspected or known to comprise eukaryotic cells, the method comprising the steps of (a) processing said liquid sample with a membrane solubilizing agent thereby lysing cell membranes of red blood cells without releasing nucleic acid and without causing precipitation of sample constituents, (b) subjecting the processed sample obtained in step (a) to a chromatographic separation, wherein said chromatographic separation is by high performance liquid chromatography (HPLC) and (c) detecting the analyte, (d) wherein said analyte is at least partially located inside a red blood cell and wherein the membrane solubilizing agent comprises a chemical selected from the group consisting of KBr, KJ, KSCN, and a salt consisting of a cation selected from the group consisting of wherein m is 0 or 1 and n is 4 or 6, and wherein the anion is selected from the group consisting of chloride, tetrafluoroborate, octylsulfate, iodide, and thiocyanate.