Fig. 4.

Registered loading of siRNAs into microwell arrays using a piezo-based inkjet printer. A) Schematic showing alignment of piezo-dispense head and a microwell array prior to dispensing of siRNA. Nanolitre volumes (8 nL) are dispensed into each microwell, coating the entire bottom surface. B) Left-Alternating design pattern programmed into the inkjet microarrayer. Right-Scan of a single microwell array loaded with Alexa-fluor-488 (green) and Cy5 (red) conjugated siRNAs using the alternating pattern. C) Top left-Design pattern 1 comprising of a quadrant to be printed into the microwell array. Top right-Scanned image of a single microwell array loaded with the quadrant pattern. Bottom-Scanned image of an entire slide (16 devices) printed in the quadrant pattern. D) Top left-Design 2 consisting of a checkered pattern to be printed into the microwell array. Top right-Scanned image of a single microwell array loaded with the checkered pattern. Bottom-Scanned image of an entire slide (16 devices) printed with the checkered pattern. Concentrations of fluorescently labeled siRNAs loaded were 5 μM in (B) and 1 μM in (C) and (D).