Red Blood Cell Fractionation by Size (Manual Counting of Red Blood Cell Subpopulations)

What This Test Measures

The test evaluates the proportion of red blood cells based on their size, often broken into categories such as small, normal, or large cells. This is done manually through microscopic examination of blood smears. While not a single numeric value, it provides qualitative insights into red blood cell morphology.

Why It Matters in Blood Health

Abnormal red blood cell size distributions can signal conditions like anemia (e.g., microcytic or macrocytic anemia), thalassemia, or other inherited blood disorders. It may also help assess conditions affecting red blood cell production or survival.

Sample Preparation and Testing Process

A blood sample is drawn and prepared as a thin smear on a microscope slide. A trained technician examines the smear under a microscope, counting and categorizing red blood cells by size. This process does not require fasting or special preparation beyond standard blood collection.

Common Conditions Affecting Red Blood Cell Size

Conditions that may lead to abnormal red blood cell size include iron deficiency (smaller cells), vitamin deficiencies (e.g., folate or B12, leading to larger cells), certain genetic disorders, or chronic diseases. This test is not a standalone diagnostic but supports broader evaluations.