AL
Mass.) proposed aliquotting frozen specimens directly with a micro-coring device that oper- ates directly on the frozen samples, including tissue and frozen liquids. Using Automated Frozen Aliquotting Technology, scientists can drill a small core out of a frozen specimen in a vial. The frozen aliquot is delivered to the sample tube, where it can be quickly heated, extracted, filtered and diluted to volume. Typical samples include urine, blood and feces.
Screening cell lines for best conditions for transfecting CRISPR plasmid libraries was the topic of a poster by Drs. Anna Lina Cavallo and Silvio Di Castro of AstraZeneca (Gothenburg, Sweden). Loading plates took too long, which reduced cell viability. With manual preparation, cell viability for the fi rst wells diff ered from simi- lar controls in the last wells. Automating plate fi lling with an Echo 555 liquid handler (LabCyte, Sunnyvale, Calif.) with OMICS S2 calibration solved the problem. Some reagents required dilution for eff ective dispensing with the Echo. However, once optimized, it was possible to quickly select the most eff ective transfection reagents and optimize the concentration.
Factors aff ecting data quality Interest in data quality was a com-
monly expressed concern and, of course, automation—reducing human involvement— provided the biggest improvements. The density of a 384-/1536-well plate taxes the lim- its of human capability. Yes, humans can load every well in the plate with a common reagent volume, but loading diff erent volumes into spe- cifi c wells becomes problematic. Uncertainty increases with the number of wells.
Automated handheld pipetting The VIAFLO ASSIST (Figure 2) from INTEGRA
Biosciences (Hudson, N.H.) automates pipet- ting into multiple-well plates. Electronic pipets can be programmed so that they can be held vertically, prewetting the tip by two or three aspirate-and-dispense cycles. Tip immersion depth can be controlled to improve preci- sion and reduce carryover. Mixing cycles are programmable in height, velocity and cycle number. ASSIST does not skips rows or wells, and users attest that it provides an economical means to improve assay precision.
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The newly designed Burdick & Jackson® website provides access to the same consistent, high-purity solvents and reagents in a variety of convenient packaging options ranging from lab scale through production. Visit
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Burdick & Jackson® © 2016 Honeywell International Inc. All rights reserved. Digital dispensing of 11-pL to
10-μL volumes For several years, scientists have wondered if direct digital dispensing technology used in inkjet printers would be adaptable for liquid dispensing. Hewlett-Packard (Corvallis, Ore.) provided a short answer: Yes! In an appar- ent OEM arrangement, Tecan (Mannedorf, Switzerland) rebranded the HP D300e to the Tecan D300 E, with which a dose from 11 pL to
10 μL can be dispensed in any well. This facili- tates direct measurement of dose response curves without serial dilution, which is vul- nerable to compounding errors. Loading a plate is generally faster, too: all that’s needed is to insert a disposable dispense head and load a small reservoir and it’s ready to run. Working with such small volumes, expensive reagents are dispersed over many more wells, reducing costs.
AMERICAN LABORATORY
17
APRIL 2016
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