Identification of Aptamers that Specifically Bind to A(1) Antigen by Performing Cell-on Human Erythrocytes

BACKGROUND: The apply of aptamers as a new generation’s way to probe diagnostic for the detection of target molecules has gained ground. Aptamers can be used as alternatives to diagnostic antibodies for detection of blood groups due to their unique features. This study was aimed to produce DNA diagnostic aptamer detecting the antigen of A(1) blood group using the Cell-Selex method. MATERIALS AND METHODS: DNA aptamer was isolated against A(1) RBC antigen after ten stages of Cell-Selex and amplification by an asymmetric polymerase chain reaction. The progress of the stages of selection was evaluated using flow cytometry analysis, which the DNA aptamer isolated from the tenth cycle with an affinity of 70% fluorescent intensity, was selected from four positive colonies followed by determination of the sequences and secondary structures. RESULTS: The aptameric sequence obtained from C(4) cloning was calculated with the highest binding affinity to A(1) antigen having an apparent dissociation constant (Kd value) of at least 29.5 ± 4.3 Pmol, which was introduced as the selected aptamer-based on ΔG obtained from a colony of C(4) equal to –13.13. CONCLUSION: The aptamer obtained from using Cell-Selex method could be used as an example for the development of diagnostic tools such as biosensors for detecting A(1) blood group antigens.