AC DEP Blood
Characterization of ABO Blood Type Erythrocytes in an AC Dielectrophoretic Device
Description and Motivation
Medical microdevices have the potential to influence the way diseases are diagnosed. One tool used in these microdevices is dielectrophoresis, or the movement of particle in an inhomogenous electric field. The use of a medical microdevice or lab-on-a-chip to identify blood related problems is a particularly attractive field in emergency medicine however the most important first step is to quantify the blood’s natural response to an electric field. Research is currently focused on defining the baseline responses of the eight blood types in the ABO typing system to an alternating current dielectrophoretic field.
An incredibly important factor when working with blood is the blood type. The ABO blood typing system was discovered by Landsteiner in 1900 . This blood typing system is defined by the presence or absence of two main antigens. These antigens are complex carbohydrates that are found on the red blood cell membrane. Type A blood is classified by the presence of the A antigen, whereas type B blood is classified by the presence of the B antigen. Type AB blood has both A and B antigens and type O blood has neither antigen . Another major factor in the ABO system is the presence or absence of powerful antibodies. Normally the body does not produce antibodies unless exposed to the antigen. However, it was found that humans naturally produce the antibody against the ABO antigens that they do not express. Therefore, blood types A and O have the B antibody and blood types B and O have the A antibody. Blood type AB does not have any antibodies. Because of this unique antigen-antibody relationship, AB is often referred to as the universal accepter and O as the universal donor . This relationship is incredibly important when a patient is receiving a blood transfusion. If the blood type does not match, the transfusion can be deadly. In addition to the A and B antigens there is a third antigen that is important in matching blood types during transfusions . This antigen is known as the Rhesus factor. If the Rh antigen is present, the blood type is classified as positive. On the other hand, if the Rh antigen is absent, the blood type is negative . Therefore, the eight resulting blood types are A+, B+, O+, AB+, A-, B-, O-, AB-.
Unaltered video microscopy images of the nonuniform electrode configuration and the spatial distribution of A+, B+, AB+ and O+ blood cells in the microdevice chamber are available in references 1 and 2. Average cell position was then tracked over time and compared between blood types. The cells with the basic polysaccharide backbone (O+ erythrocytes) were recorded with the smallest horizontal and vertical movements in the dielectrophoretic field. However, polysaccharides functionalized with N-acetyl-D-galactosamine (A+ erythrocytes) responded in the dielectrophoretic field by moving in the vertical direction away while D-galactose terminal polysaccharide cells (B+ erythrocytes) responded by moving horizontally away from the highest field density. Our group determined via statistical analysis that we could recognize O+ blood with greater than 95% confidence. This has large implications because type O blood can be universally donated. AB+ could be distinguished with greater than 85% confidence and all blood types could be distinguished from each other at a 56% confidence level.
- Landsteiner, K.Zur Kenntnis der antifermentativen, lytischen und agglutinierenden
Wirkungen des Blutserums und der Lymphe. Zbl. Bakt. 27: 357-362, 1900.
- Dailey, John F. Blood. Medical Consulting Group: 1998.
- “Rhesus blood group system”, Wikipedia.
- Minerick, A.R., “The Rapidly Growing Field of Micro and Nanotechnology to Measure Living Cells,” Invited Perspective with Cover Figure, AIChE Journal, Volume 54, Issue 9, Pages 2230-2237, September 2008.
- Keshavamurthy, S.S., P.R. Daggolu, S.C. Burgess, and A.R. Minerick, “Dielectrophoretic Characterization of Erythrocytes: Positive ABO Blood Types,” Electrophoresis, in press, 2008.
My interest in studying chemical engineering with a focus in biological engineering comes from growing up with a childhood friend who was diagnosed with Duchenne Muscular Dystrophy. My desire to succeed in this field and to further the knowledge of others comes from this very personal experience. I also have an interest in teaching at the college level because I believe there is nothing more rewarding then sharing knowledge with others and watching a future generation take that first step into a new field.