SLAS2014: Focus on Throughput and Data Quality

The 3rd annual Conference and Exhibition of the Society for Laboratory Automation and Screening, SLAS2014, was held January 18–22 in the east end of the San Diego Convention Center. In lab automation and screening, improved data quality and higher throughput are the two main drivers. Cost reduction is a distant third. Reports describing mass spectrometry for qualitative and quantitative analysis dominated the lectures in the Automation Track. Most of the applications focus on life science, especially pharmaceuticals.

Automation lectures

The scientific lecture program consisted of six parallel tracks: Automation, Informatics, Assay Development, Bioanalytical, Diagnostics and Biomarkers, and Nanotechnologies. Space does not allow coverage of the hundreds of new assays that were described.

Automated library synthesis

The drug discovery and development cycle begins with generating compound libraries, the more the better. Dr. Alberto Bresciani of IRBM Science Park (Pomezia, Italy) explained automated library synthesis in dimethylsulfoxide (DMSO). Suitable reactions usually give better than 70% purity, which is sufficient for testing without a purification step. Plus the product is in DMSO, which fits directly into many assay protocols.

Dr. David Parry of Cyclofluidic Ltd. (Welwyn, U.K.) extended the process further to a microfluidic system that increases throughput even more, giving structure activity relationships (SARs) in minutes. Integrating the synthesis with assay on a single platform is the key advance.

Detection is with MS and liquid chromatography/evaporative light scattering detection (LC/ ELSD). Reactions that do not meet acceptance criteria are excluded from the SAR.

I was particularly intrigued with the lecture from Victor Sans of the University of Glasgow (Scotland) describing fabrication of chemical synthesis workflows using 3-D printed reactionware. Reactionware combines chemicals with reactors using a logical workflow. Polypropylene is the preferred material. One example connected reactors for hydrogenation with Pd/carbon and Lewis acid catalysis reactors.

Moving downstream to formulation and process development, Dr. Eva Ping of Chemspeed Technologies (New Brunswick, NJ) described the firm’s automated workstations. Chemspeed offers automated unit operations, from synthesis reactors and incubators to product packaging. Integrated software facilitates scaleup as well as control and reporting.

Lead evaluation

Surface plasmon resonance (SPR) instruments provide convenient measures of the kon and koff of binding reactions. However, these require making runs at 6–10 concentrations to generate the binding curve. This is slow by contemporary standards. Anthony Giannetti of Genentech (South San Francisco, CA) used continuous gradients in a microfluidic device to study binding while the concentration changes by several logs. The new method is much faster, uses much less reagent, and is more automated.

Binding of proteins with ligands produces shifts in the nuclear magnetic resonance (NMR) spectrum for the atoms involved, particularly 2-D NMR of 1H and 15N. Dr. Maurizio Pellecchia of Sanford-Burnham Research Institute (San Diego, CA) showed that NMR is useful in screening large libraries (~200,000 compounds). Resonance shifts can be mapped directly to the drug-binding site, which aids in demonstrating the mechanism of action (MoA).

MS combines qualitative and quantitative analysis with high throughput

Seven lectures and numerous posters described label-free technology for screening, usually with throughput of several assays per minute. For example, Dr. Karen Maegley of Pfizer Oncology (Groton, CT) used multiple reaction monitoring in a quadrupole MS to measure the activity of isoprenal cysteine carboxylmethyltransferase. The reaction products are S-adenosyl homocysteine and methyl cysteine. The platform has been used to characterize Pfizer’s epigenetic library.

Dr. Andrew Wagner of Bristol-Myers Squibb (New York, NY) compared several approaches to high-throughput screening of libraries. One, involving high-throughput solid-phase extraction (SPE) with the ADDA system from Apricot Design (Covina, CA), gave modest purification with an analysis time of about 5 sec. However, if the SPE step is not needed, he showed that laser desorption ionization (LDI) of a porous silicon chip provides throughput faster than 1 sample/ sec. To avoid a keyhole of plate preparation, Pfizer uses acoustic nanodispensing technology to print an aliquot of the sample directly to the plate, which then goes to the LDI-TOF/MS (time-of-flight mass spectrometer).

Similarly, Dr. Scott Busby of Novartis (Cambridge, MA) developed a matrix-assisted laser desorption ionization/high-throughput screening (MALDI/HTS) platform built around the Autoflex Speed™ MS (Bruker, Billerica, MA). This is used to screen a million-well small-molecule library and products from several enzymatic assays. Throughput is 80,000 wells/day from 1536-well plates. Results were validated with comparable bridging studies with traditional, and much slower, LC/MS screens. MS-based screens appear to be more quantitative than fluorescence microscopes that so dominate the high-content analysis (HCA) market segment. Scott also offered that the waste stream from the lab was over 50 lb/day, which was a continuing issue.

Pipetting: The key to improving data quality

Discovery and development programs often involve comparing data from several sources, which use different instruments. Comparisons are more meaningful if the data are accurate and precise. Usually the largest contribution to %CV, typically 80%, is traced to the analyst. Humans get bored, fatigued, sloppy, or distracted. Since most assays are run in liquids, liquid manipulation by pipetting is common.

Other factors affecting pipetting performance were discussed in five posters from Artel (Westbrook, ME), including one on measuring nanoliter drops (www.artel-usa.com/news-events/slas/). A vendor tutorial by Keith Albert of Artel and Nat Hentz of North Carolina State University (Raleigh) demonstrated the effect of inaccurate pipetting on assay performance using two assay models. Each model consisted of three components, whereby the volume of each component was intentionally adjusted by ±10%. The impact of the variability was measured by comparing resulting IC50 potency curves. The poster addressed the effect of imprecision as measured by %RSD on IC50 values as determined by plotting activity versus concentration. The results strongly suggest that liquid handler variability affects assays. In other words, the resolution between higher-potency compounds is decreased and, likewise, important chemical scaffolds can be missed for lower-potency inhibitors. Plus, if one has a poorly performing liquid transfer in a serial dilution, errors are compounded, producing compound concentration inaccuracies larger than 50%. Thus, good practice requires properly calibrating the equipment and logging all pertinent information, including reagents, lots, instruments, protocols, and staff involved.

Pipetting workstation

The new PIPETMAX® from Gilson (Middleton, WI) is a nine-plate-capacity liquid handler designed specifically to maximize reproducibility with low- to medium-throughput assays. The liquid handler part utilizes Gilson’s time-proven PIPETMAN® single- or multichannel pipet. Setting up the PIPETMAX is very easy, with a master nine-position deck that can be loaded with source and target multiple-well plates. One opens the top, removes the old deck, and sets the new deck in place. The clear plastic lid is closed for operation. This keeps out probing hands and reduces environmental effects. The PIPETMAX is described in more detail at http://www.americanlaboratory.com/914-Application-Notes/157002-The-Scales-of-Scientific-Justice-in-Translational-Science-Data-Reproducibility-and-Verifiable-Science/.

Since Artel uncovered the need for verification of aspiration and dispense in automated analysis systems, several firms have addressed the need with different technologies. Stratec Biomedical (Birkinfield, Germany) introduced the Tholos VMI-100, which uses the pressure in the well resulting from addition of a fixed volume of gas. All 384 wells in the plate can be scanned in less than 2 min. This allows postaspirate and dispense verification for each well without regard to geometry, material well shape, etc. One can scan a virgin plate, perform several dispense and aspirate operations, and then check the final volume to verify execution of the protocol. Control and reporting are via an RS232 communication port.

SLAS exhibition

More so than any other meeting, the exhibition at SLAS is the real focus of most attendees, reflecting their practical nature. After all, automation usually implements existing and verified laboratory protocols.

In liquid handling, size matters

Automation technology is size dependent, and applications usually determine the size. For example, clinical trials usually use multimilliliter samples in phlebotomy tubes. Screening for drug leads and structure activity relationships run in plates with 384 to 1536 or more wells. Liquid handlers are challenged to deliver aliquots in the μL, nL, and now even pL range. Current air-driven pipets have an operating sweet spot for over the range of 1 μL and larger. For the nL range, acoustic dispensing seems to be the technology of choice. For pL, printer technology is showing promise.

Liquid handlers for microliters and larger

The NIMBUS 384 from Hamilton (Reno, NV) is a compact multichannel workstation for liquid transfers in 1536-, 384-, or 96-well formats. Volumes are programmable from 0.5 μL to 50 μL. The deck has room for 12 plate positions. Software control is intuitive and complies with 21 CFR Part 11.

BioMicroLab (Concord, CA) introduced the upgraded XL200 vial handling platform that includes liquid handling over the range of 5–1000 μL. The platform is the nucleus for supporting modules such as the AL LabelPro, which prints and applies machine-readable 1-D labels to sample tubes. The HS series 2-D barcode reader systems quickly read and process the barcodes on the bottom of vials. Operations are verified by weight-based sample transfer.

Andreas Kuoni, founder of Kawator (Beil, Switzerland), gave me a tour of the new multichannel OEM pipettor. It is designed to provide accurate and precise liquid handling for inclusion in applications-specific analyzers. Liquids are individually dispensed from each of the eight channels over a range of 0.5 μL–5 mL. Inboard vacuum and pressure control are used to control liquid flow to avoid daughter drops.

Liquid handlers for nanoliters

The Vantage Automated Pipettor from Hamilton provides contact-free pipetting with the NanoPulse™ technology over a volume range of 100 nL–1 mL. Hamilton expects that most Vantage systems will also use the optional logistics module that provides plate shuttling and tip replacement. Cameras have been added for traceability and detection of non-barcoded labware.

Seyonic (Neuchatel, Switzerland) introduced the Nanoliter Pipette with an eight-channel head and integrated flow sensor to manipulate liquid volumes in the range of 25 nL–10 μL. Liquids with a viscosity of 0.5–5 cP are dispensed without contact and daughter drops. Each of the eight tips is individually controlled. Precision varies with liquid dispensed. For volumes less than 50 nL, the %CV is smaller than 10%. Above 50 nL, it is less than 5%. This unit is designed to provide the liquid handling function to breadboards and OEM instruments.

Acoustic dispensing

A joint poster from Artel and EDC Biosystems (Fremont, CA) showed that EDC’s AT S-100 Acoustic Transfer System delivers drops with userselectable volumes of 1–10 nL. They note that the drop size is independent of drop order in the series. Artel’s MVS calibration protocol was used to measure drop precision. CVs for volumes delivered were in the 1–3% range for 10 nL and higher water and DMSO.

Liquid handlers for picoliters

As the scale moves down in volume from μL to nL and then to pL, the technology changes from air-driven to acoustic dispensing of individual drops in the size of 1–50 nL. For larger volumes, one simply adds more drops.

Labcyte Inc. (Sunnyvale, CA) is the acknowledged market leader. The company’s success has attracted competition. Poly-Pico Ltd. (Galway, Ireland) introduced an acoustic dispenser that deposits the liquid downward, in contrast to Labcyte’s spitting upward. The basic technology is similar to inkjet printing with drops in the pL to low-nL range. A small plastic disposable cartridge contains the fluid in a reservoir. This is placed in the small print head, which responds to calibrated computer control.

Liquid handler workstations

As noted for the last two years, the market for generic liquid handlers is well served and mature. At last year’s meeting in Orlando, FL, there were about 70 offerings. Product differentiation was obscure. As with many mature markets, the response is to repackage generics into focused applications-specific products. This facilitates product differentiation and adds value for scientists who only are interested in using the tool, not advancing the design. Some examples are below.

DNA and RNA workstation

PerkinElmer (PE) (Shelton, CT) introduced the JANUS® chemagic automated nucleic acid workstation, which improves yield four times and doubles throughput compared to other protocols. The JANUS uses magnetic beads to capture and manipulate the analytes in anticipation of sequencing or amplification. PE’s AlphaLISA® immunoassay kits provide proven protocols for many assays, including insulin, leptin, C-peptide, and FGF21.

The NIMBUS PCR workstation was one of several introductions in the Hamilton booth. The workstation uses Hamilton’s PCR module to amplify DNA in samples. The NIMBUS platform moves the samples from station to station. The company points out that the PCR workstation is vendor neutral, which makes it ideal for genotyping, pathogen detection, sequencing, etc. Hamilton also introduced workstations for selecting DNA fragments from agarose gels, immunofluorescent staining, and nextgeneration sequencing.

Arise Biotech (Taipei, Taiwan) displayed the ExMate™ Automated Pipetting System. It is a benchtop instrument that isolates the pipetting from environmental disturbances such as drafts and fingers. It is particularly useful in automating PCR and qPCR protocols. The basic LH models are the 401 and 601, but one can add a UV lamp and HEPA filters, and the 401S and 601S heating and cooling modules.

Microsonic Systems (San Jose, CA) introduced the ST30 Personal DNA Sample Prep System that utilizes Bulk Lateral Ultrasonic technology for mixing and shearing DNA into fragments of particular length from 300 to 1500 bp. The ST30 processes up to eight samples/batch, including centrifugation, to provide clean samples in 2-D barcoded vials.

Automated colony pickers

Molecular Devices (Sunnyvale, CA) showcased the QPix 400 series for more than just colony picking. It is the fastest microbial colony picker, capably picking 4000 colonies per hour. Microbial colonies ranging from E. coli, to yeast, to Streptomyces, to fungi and algae are imaged, in white light and fluorescence, to identify colonies of interest. These colonies are rapidly picked and placed into destination plates using organism-specific pins. Fluorescence imaging has given the end user more flexibility for isolating only clones of interest, minimizing downstream processing. One of the strongest new features of the 400 series is the sonic agar height sensor, which automatically detects the height of the agar to facilitate picking efficiencies of over 98%.

The custom solutions team of Molecular Devices now enables tailoring of the QPix 400 series (and all Molecular Devices products) to specific user requirements. Custom workstations integrating robotics, incubators, and software algorithms can be created to accomplish specific tasks. One example was on display—the VALet robotic arm from Thermo Fisher Scientific (Waltham, MA), which delivers destination plates for an extended, unattended run time.

In one poster, Dr. Felix Lenk of the Technical University of Dresden in Germany described a workstation called the PetriJet platform for the automated handling of Petri dishes for cell culture. A video camera from Wimass records the experiment, which can involve input and output of 20 dishes. Throughput is 80 plates/hr.

IR spectral analyzer

Infrared spectroscopy has not been much of a factor in ’omics due to the strong absorbance of water. CETICS Healthcare Technologies (Esslingen am Neckar, Germany) introduced the SEPCCs Analyzer for metabolomics, cell culture, and in vitro diagnostics. The key is the 10-μm pathlength, which is short enough to pass infrared light. Since the pathlength is short, the sample volume is less than 100 μL.

Applications examples include assay of blood lipids such as cholesterol, spectral markers for Alzheimer’s disease, and assay of cell culture growth. The information content is increased by recording the derivative spectra using a partial least squares program.

Positive-pressure solid-phase extraction module

The quality of data from screens of many compound libraries can be improved with automated sample cleanup using SPE. SPE is usually performed with vacuum assistance. This is not easily automated and lacks flow control. Hamilton introduced a positive-pressure SPE module in 24-, 48-, 96-, and 384-well formats. It is designed to fit on the deck of the company’s NIMBUS, STAR, and Vantage series liquid handlers.

Dual-arm autosampling workstation

Several of the lectures on automation reported the use of Apricot’s ADDA dual-arm autosampling workstation for high-throughput LC-MS. The cycle time is only 8 sec/sample. Throughput is rated at 4000 wells/10 hr. Most of this is a trap-and-elute cleanup. The ADDA has eight injection ports and four syringe pumps and valves. The flow path has been designed to reduce sample carryover.

Fluorescence microscope plate reader

For at least a decade, PerkinElmer’s Opera® has been the most popular fluorescence microscope plate reader for high-content analysis. PE chose SLAS to introduce the Opera Phenix™, a complete redesign with greatly improved optics that gives high-resolution sensitivity and fast 3-D four-color images. Up to four confocal images are collected using a Nipkow spinning disk camera that isolates excitation and emission light while minimizing photobleaching. An improved high-numerical-aperture water-immersion lens trebles view area. Complementary metal–oxide– semiconductor (CMOS) image sensors complement the optics to provide images of solutions and microtissues. Software integrates the images for spectacular co-localization experiments. Laser-based autofocus also enhances image quality. First shipments are scheduled for Q3, 2014.

Biobanking and sample storage

Hamilton is also a leading vendor of sample storage and banking products, including walk-in enclosures. This year, the Lab Elite I.D. Reader™ was introduced. It is designed to automatically decode 2-D barcode labels in 12-, 24-, 48-, 96-, and 384-tube racks. Identification of each tube is essential in any transfer or biobanking operation. A 96-well rack can read the labels on the top or bottom in about 3 sec. The I.D. Reader is compatible with labware from major vendors.

Hamilton’s engineers also combined the previously announced Capper with the I.D. Reader to make the LabElite I.D. Capper. This automates tube opening and tracking.

Clinical diagnostics

Years ago, the clinical diagnostics (Dx) segment split off due to divergent interests and regulatory pressure associated with CLIA and the FDA. However, I noticed a few Dx-related items such as the opening keynote, “The Convergence of the Digital Era and Medicine,” by Prof. Eric Topol, M.D., of The Scripps Research Institute (La Jolla, CA).

He asked the audience who used Twitter. He was clearly shocked when less than 10% raised their hands. During the day’s interview, I asked colleagues about this. Don Arnold of Eksigent (San Francisco, CA) summarized it best. “I’m looking for ways to increase the time between distractions.” This fits for me, also.

However, to make his point, Prof. Topol went on to show a collage of medical apps using smartphones. Some combined analytics with diagnosis. These included several that were released in the previous week. I read that his major point is that healthcare will quickly change from a physician-centric to an individual-centric model, as described in his recent book, Creative Destruction of Medicine. Automation combined with rapid, robust, and cheap diagnostics will facilitate the “Creative Destruction of [Today’s] Medicine.”

Roche (Basel, Switzerland) presented a poster describing the cobas® 6800 and 8800 systems for high-throughput diagnostics. These highly integrated workstations process 300 or 1000 samples in 8 hr. Supported test protocols are molecular diagnostics requiring PCR amplification, including HIV, HCV, HBV, and CMV.

Credits

Traditionally the January meeting of the Society for Laboratory Automation has been the forum for automation specialists to talk shop and strut their stuff. This year, 45 new products were registered. Three years ago, recognizing their symbiotic technical relationship, the Society for Biological Screening merged with the Society for Laboratory Automation to form the Society for Laboratory Automation and Screening (SLAS). SLAS2014 attracted a record 5819 scientists.

The SLAS staff and supporting volunteers deserve special thanks for organizing and managing a very successful meeting. The meeting series is now locked into alternating between Washington, DC, in odd years, and San Diego, CA, in even years. The 2015 meeting is scheduled to be held February 7–11, 2015, at the Walter E. Washington Convention Center in Washington, DC. Please visit www.slas2015.org/ for more information.

Robert L. Stevenson, Ph.D., is Editor, American Laboratory/Labcompare; e-mail: rlsteven@yahoo.com.

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