Simplification, automation, and disposability were the key themes at Knowledge Foundation’s recent “Sample Prep” conference in San Diego.
Speakers indicated that researchers’ quest for “the next big thing” is accompanied by a push among tool developers to create the tools to help them advance that endeavor. To that end, presenters outlined advances in sample preparation, highlighting new and emerging devices that streamline workflow, increase portability and disposability, combine preparation steps, and allow multiple analytes to be purified from a single sample. A universal sample-preparation process for protein, DNA, and RNA designed by Integrated Nano-Technology, (INT) meets that latter goal.
As a component of the Palladium System, sample preparation is one part of a new, automated, approach for field testing and point of care. It uses sonication and magnetic separation techniques to clean and concentrate the DNA sample for identification. INT has developed a novel fluidic system to automate the entire process. The fluidic cartridge includes a unique rotary valve that minimizes consumable costs.
The company’s goal, according to D. Michael Connolly, Ph.D., president, was to automate sample preparation and to develop a universal application. “When we set up the sonicator, we modified it to work with a wide variety of samples such as blood, tissues, and whole insects.” A sample containing spores, tissues, and viruses can be purified in Palladium, which allows efficient recovery of target molecules from difficult samples without compromising the other analytes.
This ultrasonication method uses glass beads to break the cells. The approach for protein is gentler than the approach used for DNA, but it is basically the same. The objective is to maintain the protein in its native form, without exposing it to detergents or heat, which are used in the DNA-purification process. “We’ve also made our own nanoscale particles. They bind quite effectively to the DNA, and we get very high yields,” Dr. Connolly said. Recovery rates for DNA are “better than 95 percent, and the particles also bind protein well.”
INT is engineering a device now, with development at the breadboard stage. Dr. Connolly expects the final version to measure about 6” x 6” x 4” and to operate on rechargeable batteries similar to those of a laptop.
The need for smaller sample-preparation devices is driven by the appearance of small-scale sequencing, which needs correspondingly small sample-preparation devices, as well as by diagnostics and analytical applications. Uses include biothreat analysis and veterinary diagnostics.
The point-of-care market is the target for Receptors, which is bringing its Affinity-by-Design approach to market now. Based upon CARA™ ACTIVEcapture™ technology, it offers a single solution for sample preparation that can be used in the detection and diagnosis of microbial contamination and infection control.
“There’s a huge need for organism isolation,” Robert E. Carlson, Ph.D., president and CEO, says. Traditionally, researchers had a choice between very generic methods, like centrifugation, and very specific methods, like antibody affinity capture. “There was no middle ground. ACTIVEcapture sample-preparation products bridge the critical cost versus efficiency market gap.”
CARA ACTIVEcapture technology allows multiple targets to be extracted from a single column, magnetic bead, or fiber support. “It combines the strength of an antibody affinity capture with the scalability of organic chemistry.” CARA is a combinatorial artificial receptor approach that is designed to adapt to a broad spectrum of applications by using a small library of subunits. This approach is similar to the strategy used by amino acids to create a diverse body of binding interactions.
“A few molecular building blocks are covalently immobilized to a support surface, which displays the region, stereo, and spatial relationships possible for each combination without the need for discrete synthesis.” Combinatorial arrays use multiple wells to screen against hundreds to thousands of combinations.
In contrast, with CARA ACTIVEcapture technology, “We get it all, so we screen against as many as 10,000 combinations at once. Although this display is heterogeneous at the molecular scale, it is statistically reproducible on the macro-scale. CARA provides binding space diversity and polyvalent spatial display…in a simple, economic, and flexible format.”