( Jeff Cunningham and Lynn Jord...)Sciclone ALH Bulk Dispense Precision Testing

Jeff Cunningham and Lynn Jordan
Caliper Life Sciences Inc., Applications Laboratory, Hopkinton, Massachusetts, USA

Introduction

The ability to continuously dispense reagents across multi-well plates and into individual columns (secondary dispensing) is of great importance to high throughput laboratories. Equally important, however, is the precision that can be achieved during a series of dispenses. Therefore, the bulk reagent dispensing performance of the Sciclone Advanced Liquid Handler Workstation was tested for precision. Using the absorbance properties of various tartrazine solutions, we found average variation coefficients (CV's) of <1%, 1%, 1.2% and 2.2% for volumes of 80, 40, 20 and 10μL respectively. Our data exemplifies the capabilities of the Bulk Reagent Dispenser at various microliter ranges.

Materials and Methods

Instrumentation
All testing was performed using a Sciclone Advanced Liquid Handler (ALH) and a Bulk Reagent Dispenser (Sciclone pipetting head option). Absorbance was measured at 450nm with a Wallac Victor² 1420 Multilabel Counter (PerkinElmer Wellesley, MA).

Reagents
Tartrazine (SIGMA) solutions (1.25, 1, 0.16 and 0.08g/L) corresponding to 10, 20, 40 and 80μL dispenses were prepared with deionized H₂O and degassed with Helium.

Priming
To facilitate the removal of any compressible gasses, at least three 2.5mL volumes of system fluid (in this case degassed tartrazine) are primed into a waste reservoir. Then, manual methods are used to force residual air pockets that collect at the top of the syringes into the lines by three cycles of additional priming.

Precision Determination
Tartrazine volumes (10, 20, 40 or 80μL) were d
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