Nucleated red blood cell analysis system and method

A hematology analyzer for conducting a nucleated red blood cell (nRBC) analysis on a blood sample that contains a plurality of nRBCs, the analyzer comprising:

• an excitation source positioned to excite particles within the blood sample;
• a detector unit comprising a fluorescence detector positioned to measure fluorescence emitted from the excited blood sample;
• and
• a processor
• a non-transitory computer-readable memory medium comprising instructions that cause the processor to:
• excite the blood sample with the excitation source in a flow cell;
• collect a plurality of fluorescence emission signals from the excited sample;
• and
• prior to performing an nRBC differential analysis, exclude nuclei-free events and retain nuclei-containing events using only a fluorescence trigger 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 white blood cells (WBCs) and nRBCs;
• and
• perform the nRBC differential analysis on the nuclei-containing events.