Final answer:
The number of reticulocytes can be calculated using the Miller disc method, which involves counting the number of reticulocytes in a blood sample spread onto a glass disc. Reticulocytes can be easily distinguished from mature red blood cells due to their bluish-purple color caused by residual RNA.
Step-by-step explanation:
The number of reticulocytes can be calculated using the Miller disc method. In this method, a sample of blood is spread onto the glass disc of the Miller disc. The sample is then observed under a microscope, and the number of reticulocytes is counted in a certain number of fields.
The reasoning behind this method is that reticulocytes appear bluish-purple in color due to the presence of residual RNA, which can be easily distinguished from mature red blood cells. By counting the number of reticulocytes in a specific area, an estimation of their overall number in the blood sample can be made.