Solid-phase peptide synthesis using demand mode inkjet technology

A jetlab system was built to automatically synthesize 1000 unique peptides on a membrane or glass slide. The system contains 24 single ink jet printing devices that were designed and fabricated to print the 20 different amino acids required for synthesis. The devices work on the principle of demand mode ink jet technology. The system was designed to accommodate changes in the synthesis protocol and/or substrates. The SPOT synthesis technique derived from solid phase peptide synthesis was implemented in the new system. All the batch processes, including blocking, deprotecting, activating and washing the peptide arrays, were performed simultaneously at all synthesis locations by the automated system. The enkephalin peptide, consisting of 4 amino acids and length of 5, was synthesized on a cellulose membrane derivatized with Poly Ethylene Glycol (PEG). The peptide was then cleaved from the membrane and analyzed using Matrix Assisted Laser Desorption Ionization-Time of Flight (MALDI-TOF) Mass Spectrometric Analysis. The mass spectrum obtained from the MALDI-TOF analysis shows the presence of the synthesized peptide and evaluates the performance of the demand mode ink jet technology to synthesize high quality peptides. Different peptides of various lengths can be synthesized on the same substrate. The completed high-density peptide arrays could be widely used in the medicinal research field.