The bioindustry has, in its essence, been about translational medicine, and it is strictly the rise of high throughput (and, hence, automation) that has permitted its development. As several presenters at the upcoming “LabAutomation” meeting acknowledge, effecting the subtle refinements for successful automation of cell culture, experimentation, data collection, and analysis in translational medicine R&D requires some agility of approach and an understanding of complexity.
Gary Smejkal, research assistant at the Harvard Catalyst Laboratory for Innovative Translational Technologies and an affiliate assistant professor at University of New Hampshire’s Hubbard Center for Genome Studies, likens the demands for automation to aspects of a particular myth.
“There is no ‘bed of Procrustes’,” Smejkal asserts. “In Greek mythology, Procrustes was a host who offered guests a magical bed that would adapt to one’s body size. But the bed wasn’t magical: he would either stretch guests out on a rack or cut their legs, to make them fit. The moral in automation is that there is no one-size-fits-all, whether for reagents or platforms.
“A DNA hexamer translates to about 4,096 possible sequences. By comparison, if you take a hexapeptide that is six amino acids long, you have 64 million possible sequences. It’s less straightforward than DNA analysis,” he notes. Furthermore, proteins of potential pharmaceutical interest are often expressed in low abundance, confounded further by the broad concentration range over which proteins are expressed.
“In human plasma, the mass of albumin is nearly 10 billion times greater than that of cell-signaling proteins like the interleukins,” Smejkal observes. All this creates a challenge for effective isolation and collection. Much about any sample-prep strategy will depend on the particular downstream applications and whether the proteins of interest are membrane or cytoplasmic proteins, for instance.
Smejkal cites advantages of a Pressure Cycling Technology (PCT) sample-preparation system by Pressure BioSciences that applies an oscillating pressure to release nucleic acids, small molecules, and proteins “rapidly and reproducibly,” in a way designed to minimize the denaturing effects of thermal and chemical methods. The system thus offers reported benefits over bead beaters, sonicators, homogenizers, and mortar-and-pestle grinding.
The PCT platform comprises two main components: a Pressure BioSciences Barocycler® instrument, which alternates pressures from ambient to up to 35,000 psi, and single-use processing containers called Pulse tubes.
“Proteomic sample preparation is one of the areas for which automation has the furthest to go; strides are being made but we still need better automation for proteomics. We can’t afford 80% or 70% efficiency,” Smejkal insists. “We need to access all the protein constituents of a sample, even the low-abundance proteins, and do this without bias for some proteins—for example, higher-abundance ones—over others.”
Control of flow rate and the capacity for quantification are among the key requirements for meaningful automation of sample preparation.
Scott Fulton, founder and CEO of BioSystem Development, highlights details of a platform that will be co-launched with Agilent Technologies at “LabAuto”.
The collaborative effort centers on BioSystem Development’s AssayMap® technology for high-throughput microchromatography, which is built around a cartridge device with a 5 µL volume bed of chromatographic resin (or other solid-phase support), designed to function either as a spin column or with an automated liquid-handling system. The cartridges function as miniaturized chromatography columns to allow a range of affinity-based or physical chromatographic separations and enzymatic reactions, says Fulton.
“We’ve combined Agilent’s Bravo automated 96-channel robotic liquid handlers with our AssayMAP microchromatography probe syringe technology, where the cartridge is coupled directly to small syringes mounted in the head of the liquid handler,” Fulton explains.
“These allow very precise control of flow rate, down to the microliters-per-minute range or even slower, in up to an entire microplate of 96 cartridges at once.” The result is an automated platform for “precise separations and enzymatic digestions” on disposable, 5 µL packed-bed columns in a 96-channel SBS standard microplate format.
“With the technology, we’re able to do applications like microplate ELISAs that normally might take 4 to 24 hours. With the packed-bed format and enhanced mass transport our technology affords, the binding reactions occur much faster. We can do the same ELISA on an entire plate in about 30 minutes, fully automated, without changing the reagents at all. This is critical for companies that have already invested into successful assay validation,” Fulton acknowledges.
Going forward, Agilent is to market protein-purification offerings built on the joint platform and expand the AssayMAP content portfolio. BioSystem Development will develop new chemistries and bring new “content partners” into the AssayMAP alliance, says Fulton.