Platelet measurement reagent, platelet measurement reagent kit, and platelet measurement method

A method for measuring platelets comprising the steps of:

• staining the platelets in the sample with a dye by mixing the dye, an acid and the sample to prepare a measurement sample, the dye being a compound of the following formula (II):
• wherein X is an anion selected from the group consisting of HSO4−, ½ SO42−, Cl− and ClO4−;
• applying light to cells in the obtained measurement sample to detect scattered light and fluorescence emitted from the cells;
• and
• detecting platelets contained in the measurement sample based on the detected scattered light and fluorescence.

A method for measuring platelets in a sample comprising the steps of:

• mixing a first reagent in a first container and a sample, the first reagent comprising a dye of the following formula (III):
• to stain the platelets by the dye;
• mixing a second reagent in a second container and the mixture of the first reagent and the sample to prepare a measurement sample, the second reagent comprising a buffering agent;
• applying light to cells in the obtained measurement sample to detect scattered light and fluorescence emitted from the cells;
• and
• detecting platelets contained in the measurement sample based on the detected scattered light and fluorescence.