Reticulocytes contain RNA that stains deep blue, with younger reticulocytes showing more RNA than mature ones. The corrected reticulocyte count measures red blood cell production, taking into account the normal hematocrit level. An elevated reticulocyte count indicates either increased reticulocyte circulation or decreased mature red blood cells.

4.
The RNA present in the reticulocytes stains a deep
blue.
The reticulum may be abundant or sparse, depending
on the cell's stage of development.
The youngest reticulocyte shows a larger amount of
RNA (Fig. 1 A), whereas the more mature reticulocyte
shows only a small amount of RNA (Fig. 1 C).

10. Corrected Reticulocyte Count
A reticulocyte count should reflect the total
production of red blood cells, regardless of
the concentration of red cells in the blood
(red blood cell count). The reticulocyte count
can increase either because more reticulocytes
are in the circulation, or because there are
fewer mature cells. Therefore, the observed
reticulocyte count may be corrected to a
normal hematocrit of 45%.

12. Reticulocyte Manual Count by
Supravital Stain: Normal Count

13. Reticulocytes: Elevated Count