Researchers in the groups of Professor David Barnes and Max Lagally at the University of Wisconsin have fabricated an enzyme-linked immunosorbent...
SonoPlot's Microplotter systems meet the needs of researchers looking to dispense precise picoliter volumes of fluid at specific locations on a surface.
These systems handle even sensitive biomolecules without causing deactivation through heat or shear while dispensing. This, coupled with the repeatability of the dispenses, makes these systems ideal for manufacturing protein or DNA microarrays, spotting samples or matrix for MALDI-ToF mass spectrometry, or printing microscale biosensors.
The Microplotter Proto was specifically designed based on feedback from researchers in this field. Its 20 micron positioning resolution allows for very dense microarrays to be printed. The system is compact enough to fit on a desktop, and is much less expensive than most competing systems.
Advantages Over Quill-pin and Piezoelectric Technologies
The dispensing mechanism used within the Microplotter systems is significantly different from standard quill-pin or piezoelectric technologies. A Microplotter uses controlled ultrasonics to pump fluid to the tip of a sharp glass micropipette, where the liquid meniscus is bowed out. The dispenser is then brought down to a surface and either a droplet is touched off or the dispenser is moved across the surface to draw a continuous line or arc.
The dispenser does not touch the surface when leaving behind droplets in this manner, so it is a much more gentle process than quill-pins, which often require harder mechanical tapping on a surface. A Microplotter can print on soft or fragile materials, like hydrogels, nitrocellulose, or gold-coated glass, without marking or otherwise damaging the surface.
Sub-picoliter droplets can be dispensed by a Microplotter system, leaving behind features smaller than 20 microns in width. This is significantly less than the droplet size produced by current quill-pin or piezoelectric microarray spotters. These small features are repeatable, with the Microplotter Proto capable of coefficients of variability for volumes dispensed of less than 10%.
Droplets are not ejected through the air toward the surface like in piezoelectric dispensers, so a wider variety of solutions can be printed in a Microplotter without the need to worry about clogging. Saturated salt solutions and high-viscosity materials like genomic DNA can be printed without tuning the system or solutions.