THE DEVICE AND CURRENT WORK
The current version of our device accepts either one drop of whole, undiluted blood, or 50ul of purified hemoglobin. By allowing the blood, running buffer, and antibody conjugated beads to run at separate times, the test is designed to be run in two steps, developing normal hemoglobin (HbA) and sickle cell hemoglobin (HbS) test lines in less than 30 minutes.
Early analysis of our device configuration has proven that the current design is effective at increasing the dynamic range of the test. When compared to traditional direct binding lateral flow designs requiring dilution, our device configuration increases the dynamic range from approximately 0.05 – 0.5ug of hemoglobin per test, to 0.1 – much greater than 1000ug of hemoglobin per test. These results were confirmed by the visual appearance of a test line, as well as a calculated signal-to-background ratio above a designated threshold level. Since a normal, 50ul drop of whole human blood can contain up to 2.5ug of free hemoglobin, this mechanism can therefore effectively accept a whole drop of blood without the need for a red blood cell lysing or dilution step. Current testing is also exploring the addition of lysed blood, which can contain up to 11,000ug of hemoglobin per drop of blood.