DIFFERENTIATION OF FLOW CYTOMETRY PULSES AND APPLICATIONS

• US 20120236291A1
• Filed: 05/01/2012
• Published: 09/20/2012
• Est. Priority Date: 09/29/2006
• Status: Active Grant

• Current Assignee: Cytek Biosciences Inc
• Original Assignee: EMD Millipore Corporation (Merck & Co., Inc.)
• Inventors: Pittaro, Richard, Goldman, Bruce, Lefebvre, Ray, King, David A.
• Granted Patent: US 8,885,153 B2
• Time in Patent Office: Days
• US Class Current: 356/28
• CPC Class Codes: G01N 15/14 Optical investigation techniques, e.g. flow cytometry
• CPC Class Codes: G01N 15/1429 Signal processing
• CPC Class Codes: G01N 15/1459 the analysis being performed on a sample stream
• CPC Class Codes: G01N 2015/1006 for cytology
• CPC Class Codes: G01N 2015/1477 Multiparameters
• CPC Class Codes: G01N 2015/1486 Counting the particles

Abstract

A method of analyzing pulses from a flow cytometer in which particles in a fluid pass through an excitation volume of an electromagnetic radiation and interact with the electromagnetic radiation to generate signals in the form of pulses includes generating a time-dependent pulse indicative of the characteristics of one or more particles passing through the excitation volume of the electromagnetic radiation, determining a measurement window by selecting a portion of the pulse with a starting point and an ending point above a predetermined value, and calculating a first derivative of the pulse with respect to time over the measurement window.

Claims

1. A method of tracking particles in a multi-source capillary flow cytometer comprising:

providing a first and a second excitation volumes using a first and a second light beams respectively;

passing a fluid containing particles through the first excitation volume thereby generating a first time-dependent pulse;

computing a first first derivative of the first time-dependent pulse with respect to time;

calculating a first velocity of the particle using the computed first first derivative of the first time-dependent pulse; and

determining an arrival time of the particle at the second excitation volume using the calculated first velocity of the particle.

2. The method of claim 1 further comprising the steps of:

passing the fluid containing the particles through the second excitation volume thereby generating a second time-dependent pulse;

computing a second first derivative of the second time-dependent pulse with respect to time;

calculating a second velocity of the particle using the second first derivative of the second time-dependent pulse; and

comparing the calculated second velocity with the calculated first velocity.

3. The method of claim 2 wherein the first and second time-dependent pulses are generated by scatter light from a particle passing through the first and second excitation volumes.

4. The method of claim 2 wherein the first and second time-dependent pulses are generated by fluorescence from a particle passing through the first and second excitation volumes.