Almost all biological samples exist in liquid form, and they are best kept that way. So sample handling almost always equals liquid handling. Whether liquids are being moved on a small scale by hand, one sample at a time, or on a very large scale, hundreds of samples at a time, there is a need to transfer liquids cleanly and accurately from one vessel to another. Liquid handling is a near-universal need for laboratories experimenting and studying biological sciences.
But for laboratories that pipette hundreds of samples a day, problems like repetitive stress injury and inaccurate transfers can slow down or stall progress. At one time, automated liquid handlers were found only in high-throughput or large-production laboratories. Now, with improvements that boost flexibility and functionality and can reduce costs, automated systems are becoming more commonplace in smaller labs. The same can be said about electronic and repeat pipettors. Once a luxury item in the laboratory, they are now found next to manual pipettes on the bench.
Handheld pipetting systems
Manual pipettors are a laboratory workhorse. Conventional models are designed with a disposable, friction-fit pipette tip that is ejected with the push of a button. The ability to quickly change tips enables rapid transfer of many dozens or hundreds of samples in a single session. However, there are some downsides to using a manual pipetting device. Because the tip is held on by friction, an imperfect seal can cause errors in volume transfer, or the tip may even fall off. And for heavy users, thumb-operated dispensing can cause repetitive stress injuries.
Thermo Fisher Scientific's range of liquid-handling products includes handheld pipettes (manual, electronic, single-channel and multichannel) and automated liquid handlers, such as bulk reagent dispensers, plate washers and a stand-alone pipetting system with 96- and 384-channel heads.
The company’s manual pipette line features a new system for attaching tips to the device. The company’s ClipTip interlocking tip interface uses three clips that lock the tip on and eject it with minimal pressure. “The tip is always sealed, so customers can rely on always getting consistent results,” said Suvi Malino, market and product line manager for Thermo Fisher Scientific. The ClipTip system is available for Thermo's manual and electronic lines of pipettes, but it is not meant to be used with the company’s automated systems.
The E1-ClipTip Electronic Single Channel Equalizer Pipette offers the same tip-locking system in an electronic format, with adjustable tip spacing that spares the user's hand from fatigue and repetitive stress injury. The tips also adjust to different labware formats. Thermo Fisher Scientific additionally offers a traditional, friction-fit line of pipettes for its Finnpipette and Finntip System.
Gilson is best known for its manual pipette devices: the Pipetman®, air-displacement pipettes, and the Microman®, positive-displacement pipettes for viscous and volatile liquids. For scientists requiring high sample preparation and process safety, Gilson has developed the new Pipetman M, an electronic pipette featuring an intuitive interface that offers precision and accuracy for repetitive pipetting.
Automated pipette systems
Although handheld pipettes are the most familiar liquid-handling tools, they have their shortcomings. Consistency and reliability of results, as well as user-to-user variation, are the biggest challenges of handheld systems. Automated liquid-handling systems feature near error-free pipetting and dispensing into high-density plates—up to 1,536 wells—helping researchers process large numbers of samples. Automated systems also enable researchers to perform technically challenging liquid-handling tasks, such as accurate dispensing of low (nano- and micro-molar) sample volumes and viscous or organic solutions.
Tristan Berto, product manager for Gilson shares that complexity of programming is a big concern for customers.“Most automated liquid-handling systems require lots of training and automation experience to program, so the majority of researchers in the lab can't use them without help.” Gilson offers an easy-to-use automated pipetting solutions for qPCR and other common biological applications. Gilson's most recent improvements to its Trilution micro automated pipetting software are qPCR Assistant and Normalization Assistant. "They're intuitive software solutions that help any researcher create flexible, automated runs for qPCR preparation and DNA or RNA normalization" states Berto.
Thermo Fisher Scientific is also working to make automated liquid handling more accessible to researchers, according to Tuula Jernstrom, product manager. Jernstrom shares that “many people say that the automated liquid handlers are too complicated to program. Due to this, many times people do not use these machines that they have in their labs.”
The recently introduced Thermo Fisher Scientific Versette automated liquid-handling system has easy-to-use, easy-to-learn software, with the option of either a 96- or 384-channel pipette head, making it perform much faster than a single-channel system.
BioTek Instruments recently released the MultiFlo FX Multi-Mode Dispenser, which is designed for rapid dispensing of up to four reagents into plates with as few as six wells or as many as 1,536 wells. The company also offers a wash module, for six- to 384-well plates and a Random Access Dispense (RAD) module for dispensing into individual wells on a plate. BioTek also introduced the BioSpa 8 Automated Incubator—which can link MultiFlo FX or other BioTek dispensers or washers to BioTek imaging or multimode detection systems. “It's an affordable means of automating entire workflows,” said Lenore Buehrer, senior product marketing manager at BioTek.
MultiFlo FX is designed for users who need the ability to dispense into several different plate types, or into individual wells of the plate, as well as those who prefer to combine liquid-handling activities on one platform. For cell-based assays, this system can work with sensitive cells without damaging them.
Many systems offer versatility, but this can become costly to users. Buehrer notes that the modularity of the MultiFlo FX and BioTek microplate washers enables the user to purchase only those modules that are immediately required and to upgrade as needs change. “Most of our dispensers and washers have features specific to the requirements of cell-based assays. For example, we offer angled dispense tubes, optimal plate positioning for dispensing and very low flow rates,” says Buehrer. All those features are designed to effectively process cell-based assays with minimal disruption and damage.
Hamilton’s Vantage Liquid Handling System platform is offered as a modular, configurable and expandable system with off-the-shelf components. This means customers can start with, for example, a pipettor module and add device logistics modules and transport devices to grow their system and adapt to changing needs. The Nimbus, Hamilton's entry-level liquid-handling platform, is designed to offer a higher-density workspace and increased throughput.
“Customers usually want to move their current manual benchtop protocols to an automated system. This means more than just matching their pipette volumes to one of our three platforms and requires automation expertise from the configuration, design and implementation phase,” says Hamilton marcom coordinator Claire Rhodes.
As automation becomes prevalent, more users are being exposed to new technology. To ease this transition and learning curve, both the Nimbus and Vantage Liquid Handling systems use Instinct software, which allows easy-to-use, graphical, drag-and-drop programming of assays.
Compared with other laboratory equipment, liquid-handling devices can be overlooked because they are so universal and so routine. A liquid-handling device is used in nearly every step of an experiment, from start to finish. Technicians may be comfortable with the tools they have been using for years and unaware that their workflow could be streamlined with automated liquid-handling options.
Electronic systems are available at accessible price points, with user-friendly software that takes the complexity out of programming them. There are systems designed for every application, from handling delicate cell cultures to adding sub-microliter volumes to thousands of sample wells. Looking beyond the old habits could yield great benefits in terms of efficiency, accuracy and time savings, ultimately resulting in better data.
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