Testing Information

Complete Blood Count - CBC

Red Blood Cells

The complete blood count (CBC) is one of the most common blood tests in the laboratory. The CBC is an analysis of the three major cellular components in your blood:

  • Red Blood Cells
  • White Blood Cells
  • Platelets


The advanced instrumentation that RML utilizes to count these cellular components also measures hemoglobin and gives an estimate of the volume of red blood cells in the blood. Each red blood cell contains an oxygen-carrying molecule called hemoglobin (HGB). This technology sorts the white blood cells (WBC) into five subtypes; this process is called a WBC Differential. The term ‘differential’ refers to the process of counting the different types of white blood cells that your body makes. Each type of white blood cell is present in different concentrations and reported in either percentage ratios or absolute concentrations. Here are the following types of white blood cells:

  • Neutrophils
  • Lymphocytes
  • Monocytes
  • Basophils
  • Eosinophils

How Long Does It Take To Get Results?

Wright StainIn an emergency, CBC results can be available within minutes from the time the specimen reaches the laboratory. RML utilizes the most advanced technology to provide fast and accurate results. However, sometimes the clinical picture of the patient’s test results from the instrument requires manual review by a Medical Technologist. Our instrument signals the laboratory personnel that review by a human is needed. This occurs mostly during the WBC Differential phase of the analysis and can prolong the time it takes to receive the results.

In most cases, emergency CBCs are reported back in less than an hour. Results of routine CBCs for hospital in-patients are made available in three to six hours. Majority of specimens handled at RML are for outpatient services and are usually shipped to a central location. In such cases, reports are due back at the physician’s office by the next day.