US 2014/0193851 A1 · Detecting Individual Analytes by Means of Magnetic Flow Measurement

Abstract

In a magnetic flow measurement, such as flow cytometry, individual analytes are detected in the through-flow. The analytes (e.g., cells) are marked with magnetic labels directly in the medium surrounding the analytes. The analytes are transported through the flow channel of a measuring device including at least one magnetic sensor. Using the magnetic marking of the analytes, the magnetic analyte diameter (rmag) is detected rather than the optical or hydrodynamic size (ropt) of the analytes. The analyte diameter is determined by the stray field maximum. The analyte diameter is smaller than the analyte size, such that individual analytes may be detected at high analyte concentrations.

Claims20

Dependent claims

A method for magnetic flow measurement of an analyte, the method comprising:

magnetic marking of analytes in a sample;
generating a flow of the analytes over a sensor arrangement, the flow of the analytes being guided at least over a magnetoresistive component;
generating a gradient magnetic field to enrich the marked analytes over the magnetoresistive component, and a homogeneous magnetic field, the homogeneous magnetic field and the magnetoresistive component being arranged with respect to one another such that the homogeneous magnetic field is not detected by the magnetoresistive component;
and
detecting the marked analytes individually;
wherein the magnetic marking is implemented such that each marked analyte of the analytes has a stray magnetic field with a maxima detectable by the magnetoresistive component and disposed at a distance from a center of the analyte less than a hydrodynamic radius of the analyte.

3 more elements

Dependencies are inferred from the claim text.

Detecting Individual Analytes by Means of Magnetic Flow Measurement

Life of this patent

Detecting Individual Analytes by Means of Magnetic Flow Measurement

Life of this patent

Abstract

Claims20