title: Fully automated solid weighing workstation.
abstract: A fully automated, solid-to-solid weighing workstation (patent pending) is described in this article. The core of this automated process is the use of an electrostatically charged pipette tip to attract solid particles on its outside surface. The particles were then dislodged into a 1.2-mL destination vial in a microbalance by spinning the pipette tip. Textures of solid that could be weighed included powder, crystalline, liquid, and semi-solid substances. The workstation can pick up submilligram quantities of sample (=0.3mg) from source vials containing as little as 1mg. The destination vials containing the samples were stored in a 96-well rack to enable subsequent automated liquid handling. Using bovine serum albumin as test solid, the coefficient of variation of the protein concentration for 48 samples is less than 6%. The workstation was used successfully to weigh out 48 different synthetic compounds. Time required for automated weighing was similar to manual weighing. The use of this workstation reduced 90% hands-on time and thus exposure to potentially toxic compounds. In addition, it minimized sample waste and reduced artifacts due to the poor solubility of compound in solvents. Moreover, it enabled compounds synthesized in milligram quantities to be weighed out and tested in biological assays.
authors.affiliation: Department of Neuroscience and Supply Chain Logistics, Pfizer Global Research and Development, Pfizer, Inc., Groton, CT 06340, USA. stephen_wong@groton.pfizer.com
authors.forename: Stephen K-F
authors.initials: SK
authors.lastname: Wong
authors.forename: YiFeng
authors.initials: Y
authors.lastname: Lu
authors.forename: William
authors.initials: W
authors.lastname: Heineman
authors.forename: Janice
authors.initials: J
authors.lastname: Palmer
authors.forename: Carter
authors.initials: C
authors.lastname: Courtney
mesh_terms: D000818:Animals; D001331:Automation; D002417:Cattle; D003201:Computers; D004341:Drug Evaluation / Q000295:instrumentation*; D004353:Drug Evaluation, Preclinical / Q000295:instrumentation*; D015203:Reproducibility of Results; D012709:Serum Albumin / Q000032:analysis; D013997:Time Factors
chemical_list: D012709:Serum Albumin