Method and apparatus for rapidly counting and identifying biological particles in a flow stream
A method for increasing the throughput and/or the precision of a flow cytometer, or a hematology analyzer employing a flow cytometer, and for further reducing the complexity of such a cytometer or analyzer. The system and method includes utilizing the technique of laser rastering in combination with a lysis-free single-dilution method.
1. A hematology analyzer for performing a lysis-free single dilution analysis, comprising:
(i) a light source;
(ii) a flowcell positioned to be irradiated by the light source;
(iii) at least one optical element configured to focus light from the light source onto the flowcell;
(iv) a scanning device for deflecting the focused light from the light source to enable the focused light to sweep back-and-forth across a sample stream moving within the flowcell, wherein the sample stream includes a mixture of a reagent solution, free of a lysing agent, and a sample of body fluid;
(v) at least one detector channel for obtaining a scatter or fluorescence signal emitted from a particle within the sample stream after being irradiated by the focused light; and
(vi) a processor configured to process signals from the at least one detector channel so as to analyze the irradiated particle.
2. The hematology analyzer of claim 1 , wherein the flowcell has cross-sectional dimensions sufficient to enable the formation of the sample stream such that a plurality of particles can flow along side of one another.
3. The hematology analyzer of claim 1 , wherein said scanning device is a dynamic beam deflector.
4. The hematology analyzer of claim 1 , further comprising:
a conditioning circuit for an analog signal.
5. The hematology analyzer of claim 1 , wherein said at least one detector channel comprises at least one member selected from the group consisting of: a preamplifier circuit, an analog-to-digital converter, and a field-programmable gate array.
6. The hematology analyzer of claim 5 , further comprising:
a digital signal processing chip;
an on-board memory register to hold intermediate values for computation;
and a digital-to-analog converter.
7. The hematology analyzer of claim 1 , wherein the processor is further configured to perform a time-of-flight measurement.
8. The hematology analyzer of claim 1 , wherein said scanning device is an acousto-optic modulator.
9. The hematology analyzer of claim 1 , wherein the body fluid is blood.
10. The hematology analyzer of claim 1 , wherein the body fluid is selected from the group consisting of: cerebrospinal fluid, pleural fluid, peritoneal fluid, pericardial fluid, synovial fluid, ascites fluid, drainage fluid, and dialysate fluid.
11. The hematology analyzer of claim 1 , wherein the sample of body fluid is homogenized by inversion.
12. The hematology analyzer of claim 1 , wherein the reagent solution comprises a saline diluent.
13. The hematology analyzer of claim 12 , wherein the reagent solution further includes a sphering reagent.
14. The hematology analyzer of claim 13 , wherein the reagent solution further includes at least one nucleic acid dye.
15. The hematology analyzer of claim 14 , wherein the at least one nucleic acid dye is capable of staining RNA.
16. The hematology analyzer of claim 14 , wherein the at least one nucleic acid dye is capable of staining DNA.
17. The hematology analyzer of claim 13 , wherein the reagent solution further includes a selective permeabilizing agent.