At EMD Millipore, Sébastien Ribault, Ph.D., head of predevelopment-technology-collaboration, biomonitoring R&D, lab solutions, detailed a nucleic sample preparation kit called MilliPrep. “We’re not developing protein sample preparation with it. We’re removing protein from the sample.” This kit, he said, is a response to a sample-preparation technology that was time-consuming, generated false positives because of the steps required for sample preparation, and was not adapted for the molecular biologists’ workflow.
MilliPrep fully integrates the sample-preparation steps within a single, three-step, closed system that combines membrane-based filtration and magnetic bead nucleic acid purification.
To separate eukaryotic cells from mycoplasms, for example, users pipette the sample into the upper chamber of the device and place the device into a centrifuge, where the eukaryotic cells are retained on a membrane between the sample chamber and the capture chamber. “In this step, 99.9 percent of the protein and other contaminants are removed,” Dr. Ribault said.
Mycoplasma are trapped on an asymmetric membrane, and fluid is drained into a waste tank at the bottom of the cartridge. “The remaining 0.1 percent of contaminants is removed with the fluid.” Then, a lysing reagent is added. The sample is incubated and then centrifuged again to recover targeted mycoplasma nucleic acids.
According to Dr. Ribault, “The process eliminates false positives. It processes 20 mL volumes, which are 20 times higher than traditional column methods. Hands-on time is less than 30 minutes for ten devices.”