Method for flagging a sample

A hematology analyzer comprising:

• a) a flow cell;
• b) a light source for directing light to said flow cell;
• c) a plurality of detectors for detecting a plurality of optical characteristics of a blood sample passing through said flow cell;
• and
• d) a data analysis workstation comprising a processor, wherein the processor comprises a non-transient computer-readable medium programmed with instructions that, when executed by the processor, cause the hematology analyzer to:
• i) pass the blood sample through the flow cell and direct the light source to the flow cell to generate a plurality of optical data using the plurality of detectors;
• ii) analyze the optical data to determine one or more values for the blood sample, wherein the value is selected from the group comprising:
• a rate of decrease in the total number of cells in the blood sample over a period of time, a rate of decrease in the number of cells in the blood sample classified as lymphocytes over a period of time, a lymphocyte geometric distance, a lymphocyte box count ratio, or a lymphocyte depolarized side scatter (DSS) value;
• and
• iii) calculate the difference between each value and a reference criterion that is based on data obtained from a plurality of reference samples, wherein if the value differs from the reference criterion by a predetermined amount, then the blood sample is flagged as containing lysis-resistant red blood cells or fragile white blood cells.