We have 68.9 µM of aptamer stock concentration. During SELEX procedure we have taken protein coated Ni-NTA beads & we have taken 7.25 µl aptamer having concentration of 68.9 µM, then diluted it with 42.75 µl binding buffer (20mM Sodium phosphate, 500mM Sodium chloride, 5mM Imidazole). So the final working concentration of our aptamer is 10 µM in 50 µl total volume. Whether final aptamer concentration of 10µM matters or we can take directly 10µM aptamer for SELEX procedure?