Final answer:
The Hematology Analyzer is the instrument designed to count RBCs, WBCs, and platelets; measure hemoglobin concentration; and calculate RBC indices, as well as to evaluate other cellular features.
Step-by-step explanation:
The instrument used to count red blood cells (RBCs), white blood cells (WBCs), and platelets, to determine hemoglobin concentration, and to calculate RBC indices is a Hematology Analyzer. This device also determines cell size and can evaluate cell parameters such as the granularity of the cytoplasm and the shape of the nucleus for WBCs. Furthermore, in a clinical setting, the hematocrit test, which can be performed using a centrifuge, measures the percentage of RBCs in a blood sample. The hematocrit separates blood into layers, with erythrocytes at the bottom, the buffy coat containing leukocytes and thrombocytes above it, and plasma on the top. Microscopic evaluation of blood, such as counting cells using a hemocytometer or Petroff-Hausser chamber, and the direct observation of smears, are other methods used to analyze blood components systematically. Automated methods in clinical laboratories further aid in distinguishing and counting blood cells efficiently.