A system for conducting an optical mean corpuscular volume analysis of red blood cells on a sample of whole blood, the system comprising: (a) a hematology analyzer, the hematology analyzer comprising: a flow cell; an excitation source positioned to excite particles within the blood sample as it is passed through the flow cell; a plurality of detectors including an axial light loss detector positioned to measure axial light loss from the excited blood sample, an intermediate angle scatter detector positioned to measure intermediate angle scatters from the excited blood sample, a polarized side scatter detector positioned to measure large angle polarized side scatters from the excited blood sample, a depolarized side scatter detector positioned to measure large angle depolarized side scatters from the excited blood sample; and a processor configured to: receive the measurements of axial light loss, intermediate angle scatters, large angle polarized side scatters, large angle depolarized side scatters, and perform an MCV analysis of red blood cells of the blood sample, based on a plurality of optical data received from the detectors and without the use of electrical impedance components; and (b) a hematology reagent fluidly coupled to the hematology analyzer for optical MCV analysis of red blood cells, the hematology reagent comprising: a non-phosphate organic buffer; a sphering surfactant; and an osmolality adjustment component, wherein the hematology reagent has sufficient optical clarity to facilitate optical MCV analysis of the sample. (a) a hematology analyzer, the hematology analyzer comprising: a flow cell; an excitation source positioned to excite particles within the blood sample as it is passed through the flow cell; a plurality of detectors including an axial light loss detector positioned to measure axial light loss from the excited blood sample, an intermediate angle scatter detector positioned to measure intermediate angle scatters from the excited blood sample, a polarized side scatter detector positioned to measure large angle polarized side scatters from the excited blood sample, a depolarized side scatter detector positioned to measure large angle depolarized side scatters from the excited blood sample; and a processor configured to: receive the measurements of axial light loss, intermediate angle scatters, large angle polarized side scatters, large angle depolarized side scatters, and perform an MCV analysis of red blood cells of the blood sample, based on a plurality of optical data received from the detectors and without the use of electrical impedance components; and a flow cell; an excitation source positioned to excite particles within the blood sample as it is passed through the flow cell; a plurality of detectors including an axial light loss detector positioned to measure axial light loss from the excited blood sample, an intermediate angle scatter detector positioned to measure intermediate angle scatters from the excited blood sample, a polarized side scatter detector positioned to measure large angle polarized side scatters from the excited blood sample, a depolarized side scatter detector positioned to measure large angle depolarized side scatters from the excited blood sample; and a processor configured to: receive the measurements of axial light loss, intermediate angle scatters, large angle polarized side scatters, large angle depolarized side scatters, and perform an MCV analysis of red blood cells of the blood sample, based on a plurality of optical data received from the detectors and without the use of electrical impedance components; and receive the measurements of axial light loss, intermediate angle scatters, large angle polarized side scatters, large angle depolarized side scatters, and perform an MCV analysis of red blood cells of the blood sample, based on a plurality of optical data received from the detectors and without the use of electrical impedance components; and (b) a hematology reagent fluidly coupled to the hematology analyzer for optical MCV analysis of red blood cells, the hematology reagent comprising: a non-phosphate organic buffer; a sphering surfactant; and an osmolality adjustment component, wherein the hematology reagent has sufficient optical clarity to facilitate optical MCV analysis of the sample. a non-phosphate organic buffer; a sphering surfactant; and an osmolality adjustment component,