White blood cell analysis system and method

摘要

Systems and methods for analyzing blood samples, and more specifically for performing a white blood cell (WBC) differential analysis. The systems and methods screen WBCs by means of fluorescence staining and a fluorescence triggering strategy. As such, interference from unlysed red blood cells (RBCs) and fragments of lysed RBCs is substantially eliminated. The systems and methods also enable development of relatively milder WBC reagent(s), suitable for assays of samples containing fragile WBCs. In one embodiment, the systems and methods include: (a) staining a blood sample with an exclusive cell membrane permeable fluorescent dye, which corresponds in emission spectrum to an excitation source of a hematology instrument; (b) using a fluorescence trigger to screen the blood sample for WBCs; and (c) using measurements of (1) axial light loss, (2) intermediate angle scatter, (3) 90° polarized side scatter, (4) 90° depolarized side scatter, and (5) fluorescence emission to perform a differentiation analysis.

主权项

1. A method of performing a white blood cell (WBC) analysis with an automated hematology analyzer, the method comprising:
(a) diluting a sample of whole blood with a WBC reagent, wherein the WBC reagent includes a red blood cell (RBC) lysing agent and a fluorescent dye that penetrates WBC membranes and binds to WBC nucleic acids; (b) incubating the diluted blood sample of step (a) for an incubation period of time; (c) delivering the incubated sample from step (b) to a flow cell in the hematology analyzer; (d) exciting the incubated sample from step (c) with an excitation source as the incubated sample traverses the flow cell; (e) collecting a plurality of light scatter signals and a fluorescence emission signal from the excited sample; (f) prior to performing a WBC differential analysis, excluding nuclei-free particles and retaining nuclei-containing particles using only a fluorescence trigger configured in the hematology analyzer and that is limited to fluorescence emission signals and is set to a fluorescence magnitude that is greater than fluorescence emission signals from RBCs, including RBC fragments, and is less than fluorescence emission signals from WBCs; and (g) performing the WBC differential on the nuclei-containing particles retained in step (f).