As the Con A aptabody is highly specific, we opted to make the process a single step methodology by excluding the prior downstream processing steps. For this reason, we have loaded the crude extract of jack bean over chromatographic column without any intermediate purification. After completion of binding reaction, the affinity retained molecules were separated and eluted in high salt buffer. Elution of the target molecules from column can be performed either by adding denaturing agents, organic modifiers or by competing agents to the mobile phase, or by changing its pH or temperature during elution. As non-covalent forces constitute the basis of aptamer–protein interaction, we modulated the ionic strength of the mobile phase using high salt concentrations (0.25–2.0 M NaCl) to break the weak non-covalent forces and elute the target proteins. As shown in Fig. 2, 1.5 M NaCl was found to elute maximum protein from support with no effect of further increase in salt concentration. Probably, the smaller size and high target affinity of aptabody has played a crucial role in target purification. As small size of aptabody allows high surface coverage (density) over solid support, the accompanying high affinity and specificity ensures maximal target retention. These presumptions appear true by the obtained yield, purity and recovery of the purified Con A.