Sickle cell disease (SCD) is an inherited disorder of the beta globin gene that causes red blood cells to deform into sickle cells. It can cause anemia and blockages in blood flow resulting in severe pain episodes. While developed countries have the necessary resources to effectively diagnose SCD, underdeveloped countries lack finances, reliable electricity, and the climate control necessary for modern diagnostic testing. Our lab has modified the sodium metabisulfite based-test to differentiate the homozygous genotype (SS/SCD) from the heterozygous genotype (AS/sickle cell trait[SCT]). We hypothesize that the number and intensity of sickled cells over time can help differentiate SCD from SCT. Fifteen microliters of 2% sodium metabisulfite solution was combined with fifteen microliters of patient blood and incubated at room temperature for 3 hours. The number of fully formed sickle cells (4+ on a 1-4+ Likert scale) were counted under 100x oil immersion for each genotype and for negative controls. Forty-four SS samples produced an average of 127.5 sickle cells (4+) in 3 hours whereas four AS samples produced an average of 17.8 sickle cells (4+) at 3 hours. Because of the low sample number in the AS group (N=4), a non-parametric independent t-test was performed producing a p-value of 0.000068 which indicates a significant difference in the number of 4+ sickle cells after 3 hours between the SS and AS groups. These findings are promising because the method is accurate, inexpensive (less than $1.00/test), simple, and relatively rapid as other testing can be done during the incubation phase.

Nikhil Jacob would like to thank his research mentor, Dr. Tim Randolph, for his support during this project.