Shusuke Sato

Microintaglio Printing of In situ Synthesized Proteins Enables Rapid Printing of High-Density Protein Microarrays Directly from DNA Microarrays

A simple and versatile approach to the simultaneous on-chip synthesis and printing of proteins has been studied for high-density protein microarray applications. The method used is based on the principle of intaglio printing using microengraved plates. Unlike conventional approaches that require multistep reactions for synthesizing proteins off the chip followed by printing using a robotic spotter, our approach demonstrates the following: (i) parallel and spotter-free printing of high-density protein microarrays directly from a type of DNA microarray and (ii) microcompartmentalization of cell-free coupled transcription/translation reaction and direct transferring of picoliter protein solution per spot to pattern microarrays of 25–100 µm features.

Evaluation of poly(dimethylsiloxane) microreactors for pattern size miniaturization of microintaglio-printing-based protein microarray

We developed a soft lithography-based microintaglio printing method for fabricating robot-free high-density protein microarrays using a poly(dimethylsiloxane) (PDMS) microchamber array. This method provides a simple approach to simultaneously synthesize and capture functional protein microarrays (with 25?100 ?m resolution in this study) directly from DNA microarrays in situ on a chip without a spotter and therefore can be an extremely effective tool for the miniaturization of arrays. However, minimizing the scale, which increases the PDMS surface area to sample volume ratio, can alter arraying outcomes because of interfacial phenomena. In this study, we evaluated the suitability of PDMS for miniaturizing cell-free synthesis-based protein microarrays and showed that the amount of a green fluorescent protein synthesized in situ inside PDMS microchambers monotonically decreased with decreasing microchamber (pattern) size and that the protein could not be detected in microchambers with a diameter smaller than 25 ?m. The impact of absorption and/or adsorption on the PDMS surface on protein synthesis inside the microchamber was observed, which was reduced by coating techniques. The results obtained here clearly suggest that PDMS interfacial phenomena can be suppressed while obtaining the benefits of cell-free protein synthesis and microintaglio printing, as a step toward developing ultrahigh-density protein microarrays.