Multi-frequency impedance method and apparatus for discriminating and counting particles expressing a specific marker
AssigneeKoninklijke Philips Electronics N.V.
InventorsHywel Morgan, David Holmes
Life of this patent
Estimating the term…
Abstract
An analysis method for identifying and counting particles expressing a specific antigenic marker is proposed. One example (but not exclusive) is CD4+ T-lymphocyte analysis in blood. The method comprises obtaining a sample comprising particles in suspension, labeling the particles expressing the specific marker with an impedance label, and measuring the labeled sample using a dual frequency system to discriminate at least the labeled particles expressing the specific marker. The method allows an accurate count of particles e.g. the number CD4+ T-lymphocytes in a blood flow. A corresponding device is also provided.
Claims13
An analysis method for identifying and counting particles expressing a specific marker, the method comprising:
- obtaining a sample comprising particles,
- labeling the particles expressing the specific marker with an impedance label, measuring the labeled sample using a plural frequency system to discriminate at least the labeled particles expressing the specific marker.
A device for identifying and counting particles expressing a specific marker, comprising
- a micro-channel for comprising a sample flow comprising labeled particles expressing the specific marker,
- at least one pair of electrodes,
- electronic circuitry for applying at least a first AC signal at a first frequency and a second AC signal at a second frequency to the at least one pair of electrodes, the first frequency being lower than the second frequency,
- a calculation unit for determining the impedance of a particle present between the pair of electrodes, the calculation unit being adapted for determining the impedance of the particle at least at the first frequency and at the second frequency, for correlating the impedance at the first frequency to the opacity being the ratio of the second frequency impedance to the first frequency impedance, and for discriminating from this correlation at least the labeled particles expressing the specific marker.
Dependencies are inferred from the claim text.