Resuspend 2 nmol de la library pool on 200 µl of Binding Buffer (BB).
Denatured the library by heating it at 90ºC for 10 min and immediately cold it on ice for another 10 min.
To get rid of the DNA that unespecifically binds to the system, apply the library through a nitrocellulose membrane and centrifuge 1 min at 8000 rpm. Quantify the DNA that does not bind unspeficically and note it as the initial DNA.
Protein-Aptamer incubation
Incubate the flowthrough with the protein of interest during 1 hour.
Apply the DNA to a new nitrocellulose membrane as in step 3.
Wash the membrane four times with 300 µl of BB, like on step 3.
Recover the membrane and transfer it to a new Eppendorf tube without letting it dry.
