Clinical Centrifuge for Medical Diagnoses

By Mitch Griffith Ph.D

In medicine, a CBC - Complete Blood Count- is a commonly requested blood test. This test can provide a valuable insight into a patient's health, including information on possible diseases.

Blood Basics

The main components of the human blood are fluid (plasma) and blood cells. In addition to the plasma a Complete Blood Count or CBC provides details about the three main blood cell types in the blood. A clinical centrifuge is generally used to isolate or separate the main blood cell types to aid in the diagnosis of possible diseases. The four components are:

• Plasma

  This fluid in the blood contain nutrients such as sodium, calcium, potassium, amino acids, urea, hormones, lipoproteins and other materials which are helpful to the normal functioning of the organs and cellular bodies.

• Red Blood cells (erythrocytes)
  
  

  These are the most numerous blood cells. Red blood cells carry hemoglobin, an iron-rich substance that transports oxygen throughout the body. These blood cells are also responsible for removing carbon dioxide from the tissues in the body.

  
  
• White Blood Cells (leukocytes)
  
  

  These blood cells protect the body against infections and diseases. There are several types of white blood cells.

  
  
• Platelets (thrombocytes)
  
  

  These cells play a vital role in blood clotting.

Analyses and Results

When a CBC is requested, the venous blood drawn from the patient by a certified technician is taken to the laboratory and a clinical centrifuge is used to separate the plasma from the blood cells. Other equipment is used to analyze and identify the cells.
The number of red and white blood cells and platelets are identified and counted. This analysis measures the population and characteristics of the cells as follows:

• Hemoglobin and Hematocrit
  
  

  Hemoglobin is the oxygen carrying substance in red blood cells. Hematocrit refers to the proportion of the blood that is composed of red blood cells. Low levels of these two measurements mean that there is a possibility of anemia. Having too many red blood cells suggests a condition called poly-cythemia. Poly-cythemia vera is a blood cancer that causes red blood cells to multiply. Hemoglobin is measured in grams per deciliter (g/dl) where the normal range is 12.0 - 15.5 g/dl. The Hematocrit is measured as a percentage where the normal range is 34.9 - 44.5 %.

  
  
• Mean Cell Volume (MCV)

  This measurement relates to the size of the red cell. MCV is helpful in evaluating anemia. If the MCV is too high, it may suggest the possibility of a deficiency of Vitamin B-12. High levels are sometimes related to excessive intake of alcohol or other conditions. If the MCV is too low it may suggest an iron deficiency or a genetic blood cell condition. In both men and women the normal range for MCV based on the average size of the red blood cells measured in femtoliters (fL) is 80 - 100 fL.

• Leukocytes (White Blood Cells)

  This is a measure of the number of white blood cells in the blood. A moderate elevation in the number of the number of these cells may indicate an infection or inflammation. Very high levels may indicate a bone marrow disorder, such as leukemia. Low white blood cell levels may indicate a viral infection.

  If the low blood cell levels are persistent, this may be related to a problem with bone marrow production of blood cells such as aplastic anemia or other serious conditions. A reduced number of red blood cells cause the hemoglobin to drop to drop and a reduced number of white blood cells make the patient susceptible to infection. A reduced number of platelets decrease the clotting efficiency of the blood.

• Differential White Blood Cells

This white blood cell count is a breakdown of the different types of white blood cells in the human blood. Usually the white blood cells are divided in to five types:

• Neutrophils
  
  

  These white blood cells increase in response to an infection in the body and help destroy bacterial infection. Neutrophils often comprise the highest percentage of white blood cells. The normal range is 42 - 75%.

  
  
• Monocytes
  
  

  These white blood cells are like scavengers. They help remove foreign elements and microorganisms from the blood. The normal range is <11%.

  
  
• Lymphocytes

These cells help identify foreign elements or other "invaders" in the body, then they make antibodies to fight them. Very high levels of lymphocytes may be associated with a common type of leukemia called chronic lymphocytic leukemia. A moderate elevation of lymphocyte cell count may indicate a viral infection. The normal range is 16 - 52%.

• Eosinophils
  
  

  Elevated levels of these white blood cells indicate an allergic reaction or a parasitic infestation. The normal range is <7%

  
  
• Basophils

These cells are associated with allergic reactions to drugs or other substances. The normal range is <4%

• Platelet Count

  Bleeding and clotting problems can arise when platelet levels are too high. Bleeding can also occur if levels are substantially below normal. The number of platelets in a micro liter of blood determines a platelet count. The normal range is 150,000 - 450,000.

  If the platelet count numbers indicate a possible abnormality, a blood smear may be done. A drop of blood is smeared on a slide and then viewed under a microscope. Abnormal red blood cell shapes can signal disease, such as sickle cell anemia or abnormal hemoglobin (thalassemia). A smear can also detect parasites in the blood, such as those associated with malaria.

Finally, helpful information can be found in a small sample of blood. Tests like Complete Blood Counts are important resources for determining general state of health and possible uncovering a condition that warrants further testing and treatment. A clinical centrifuge plays an important part in the diagnosis and treatment of different diseases.