Microarrays have a wide application in medical biology, where sets of miniaturized chemical reaction areas may be used to test DNA fragments, antibodies, or proteins. The slides or chips have immobilized targets that are hybridized with probed samples. After hybridization, the fluorescent color from the chip can be scanned and the data analyzed by specific software to find the expression level.

In a study, carried out at Arizona State University (ASU; Tempe, AZ, USA), peptide microarrays, consisting of 10,000 20-residue peptides of random amino acid sequences were tested with human and mice sera to ascertain the humoral immune response to the influenza virus infection and vaccination. The results of the study showed that the technique could distinguish between infected and noninfected mice and the immunosignature was stable over time and dose dependent. This test could distinguish between the immune response to different infections such as influenza and tularemia.

Peptide microarrays have a great advantage over traditional antibody-antigen tests, such as enzyme-linked immunosorbent assays (ELISA), which are usually disease specific. In the ELISA test, antigens are absorbed on to a microplate, which will only bind with specific antibodies. By contrast, immunosignaturing provides a universal platform, capable of detecting subtle transformations over the entire antibody profile, regardless of the underlying cause.

Joseph B. Legutki, Ph.D., who pioneered the method for profiling the immune system at ASU, said, "The immune system is exquisitely sensitive to any alterations in an individual's state of health resulting from infection or disease, registering these changes through subtle fluctuations in antibody activity. We just need to interpret the message." The study was published in June 2010 in Vaccine.


Related Links:
Arizona State University