The disclosure provides a sample testing method and a sample analyzer, the method including: obtaining a sample to be tested; providing a reagent, the reagent including a hemolytic agent, a first fluorescent dye and a third fluorescent dye; mixing the sample and the reagent to form a sample solution; making the sample solution flow in a flow cell in a single test, irradiating the particles by using a first light source and a second light source, and detecting scattered light signals, first fluorescence signals and third fluorescence signals; obtaining a classification result and/or a counting result of white blood cells in the sample to be tested based on the first fluorescence signals and the scattered light signals; and obtaining a counting result of nucleated red blood cells in the sample to be tested based on the third fluorescence signals and the scattered light signals.

A blood analyzer according to one or more embodiments may include: a specimen preparation part that prepares a measurement specimen by mixing a reagent into a blood preparation; a measurement part that measures the measurement specimen; a measurement mode selection unit that receives an input of a type of blood preparation as a measurement target selected from a plurality of types of blood preparations; and a controller. The controller may cause the specimen preparation part to prepare the measurement specimen depending on the selected type of blood preparation.