omation mbers - Society for Laboratory Automation and Screening

WP055
Donald Schwartz
DRD
83 Pine Street
West Peabody, Massachusetts 01960
donschwartz@drddiluter.com
218
Co-Author(s)
Donald S. Martin
First Dual Resolution Syringe (DRS), Using Differential Displacement, for Practical Contact-
Free Nanoliter Transfer of Discrete Samples or Within-tip Mixtures, and Extreme Dilutions
The unchallenged aspiration supremacy and reliability of smooth motor-controlled positive displacement syringe
devices has been sullied by small seal and bubble hassles and recently overwhelming demands for ever-finer
resolution without loss of blowout power. Awesome complexity has spawned to try to compensate for the
shortcomings. The Dual Resolution Syringe (DRS) (patented and patent-pending) is a syringe with a glass barrel
the same ID as a 1 mL syringe, with a sturdy little spring-loaded piston that is slightly smaller than the glass barrel
ID. The piston can move in and out of the barrel, coordinating with the plunger. When the two move together
(DRD Differential Mode) the cross sectional area difference and resolution are like a 10 µL (or even 1 µL) syringe,
aspirating smoothly down to 10 nL. Then the plunger moves alone (DRD Bulk Mode), delivering abundant flow
power (like a 1mL syringe) to blow the minute sample out, which it can do at well over 1.5 meters/sec through any
diameter tip, intact and without damage (Blastoff), to its microplate, array, spotting or Maldi target. Samples and
reagents can also be mixed inside certain tips and the mixture delivered contact-free.
DRD has thus endowed the syringe with its Differential Displacement capability. This preserves the classic
strengths of venerable classic syringe technology, eliminates shortcomings, and enormously enhances its range
and analytical flexibility. The elimination of small seals and crannies, and the high flow priming throughout, also
greatly increase reliability and longevity. The DRS directly replaces a conventional syringe in its host system.
Substituting a DRS for a conventional 250 µL syringe, for example, immediately gives 25X finer resolution for
aspiration, 4X more flow power for delivery, and within-tip mixing capability. This model can also aspirate a 10 nL
sample and dilute it 30,000:1. The DRS debuts as individual units and as a bank of eight 9 mm-spaced units for
contact-free transfer of drops down to 10 – 25 nanoliters.