LabAutomation 2006 - SLAS

MP11
Sibani Biswal
University of Berkeley
Mechanical Engineering
Palo Alto, California
sbiswal@berkeley.edu
LabAutomation2006
Co-Author(s)
Digvijay Raorane
Arun Majumdar
Alison Chaiken
HP Labs
Using a Microcantilever Array for Detecting Phase Transitions in Polymers
We report the extension of the microcantilever platform to study the thermal stability of macromolecules. The sensitivity of these cantilevers
combined with their fast response time has allowed us to use these sensors for the thermal analysis of phase transitions in adsorbed
molecular films. Microcantilevers have become important micromachined structures for many physical, chemical, and biological sensing
applications. Their extremely high surface-to-volume ratio permits detection of surface stresses which are too small to observe on a
macroscale to become an important sensing mechanism.
Microcantilever-based sensors directly translate changes in Gibbs free energy due to analyte-adsorbate and adsorbate-adsorbate
interactions into mechanical responses. The cantilever thereby transduces a biochemical signal into a mechanical one. One can
follow surface processes by measuring the deflection of the cantilever tip. We utilized this phenomenon to study phase transitions in
macromolecules while scanning the sample temperature or varying salt concentrations. To demonstrate the use of the microcantilever to
detect phase transitions, we have studied the melting of DNA molecules. Using the microcantilevers, we are able to explore the stability of
DNA under a variety of solution conditions. Differences in the lengths and intermolecular interactions between single- and double- stranded
DNA are highlighted by variations in cantilever deflection. Additionally, we have used the microcantilevers to observe changes in polymer
brush height due to salt changes. This new technique has allowed us to probe polymer dynamics and leads to a better understanding of
the stability of polymer complexes on surfaces.
MP12
Wayne Bowen
TTP LabTech
Melbourn, Hertfordshire,
UK
wayne.bowen@ttplabtech.com
Co-Author(s)
Rose Hughes
Jose Quiroz
Robert Bukar, Kalypsys Inc
Joby Jenkins, TTP LabTech
A Solution for Serial Dilution of Compounds in 1536-Well Microplates
High-density screening platforms are an integral part of any successful high-throughput screening facility. Increasing well density
shrinks assay volumes, which correspondingly minimizes reagent costs, accelerates assay throughput, and can improve assay quality
and reproducibility by reducing assay duration. Kalypsys’ suite of ultrahigh-throughput robotic screening technologies has enabled
unprecedented levels of efficiency and economy in a host of screening operations. Based around 1536-well microplates, the Kalypsys
System combines the throughput of 1 million assay wells per day with on-line storage capacity for over 2 million compounds. This focus on
1536-well miniaturization has created a need for liquid handlers that are capable of accurately and reliably transferring and diluting nanolitre
volumes of liquid. Kalypsys had been unable to identify a technological solution for 1536-well serial dilution, until the mosquito ® .
The mosquito ® is an innovative nanolitre pipettor that combines the liquid transfer capability of a fixed head dispenser with the convenience
and zero cross-contamination of disposable tips. The mosquito ® is capable of pipetting volumes from 1.2 mL down to 50 nL with no
washing required. Here we demonstrate the application of a mosquito ® for serial dilution of compounds in 1536-well microplates for
profiling in biochemical assays.
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