Method of isolating aptamers for minimal residual disease detection

A method for selecting and isolating aptamers that target M-Ig proteins, comprising:

• a) providing a microdevice to select and isolate M-Ig targeting oligomers comprising:
• a first selection chamber for positive selection,
• a second selection chamber for counter-selection, wherein the first selection chamber is connected to the second chamber via a first channel,
• a third selection chamber for negative selection, wherein the second selection chamber is connected to the third selection chamber via a second channel, and
• an amplification chamber, wherein the amplification chamber is connected to at least one of the first chamber, second chamber, and third chamber via a third channel, wherein the first, second, and third channels are configured to hydrodynamically and/or electrokinetically transfer a solution;
• b) obtaining a first sample of M-Ig proteins from a serum;
• c) placing the first sample of M-Ig proteins in the first selection chamber;
• d) placing a second sample of M-Ig or polyclonal immunoglobulin proteins having a heavy and light chain substantially similar to the first sample of M-Ig proteins in the second selection chamber;
• e) placing beads without a molecular coating in the third selection chamber;
• f) introducing a first group of oligomers including at least an M-Ig targeting oligomer into the first selection chamber, whereby the M-Ig targeting oligomer binds to the first sample of M-Ig proteins;
• g) removing unbound oligomers from the first selection chamber to isolate the M-Ig targeting oligomer;
• h) transferring the M-Ig targeting oligomer to the second selection chamber, whereby an unbound oligomer is counter-selected;
• i) transferring the counter-selected unbound oligomer to the third selection chamber, whereby a subsequent unbound oligomer is negatively selected from the counter-selected unbound oligomer;
• j) transferring the subsequent unbound M-Ig targeting oligomer to the amplification chamber through the second channel by a pressure-driven or electrokinetic-driven flow;
• and
• k) amplifying the M-Ig targeting oligomer in the amplification chamber by polymerase chain reaction.