Miltenyi Biotec GmbH, Bergisch Gladbach, Germany, a global provider of products and services for biomedical research and cellular therapy, has signed a purchase contract for a non-harmful, fluorescence-preserving, optical clearing process from the University of Duisburg-Essen. The university had previously registered the new process for international patent approval.

The acquired invention involves an easy-to-use protocol that permits safe optical clearing of biological samples for microscopy using an organic solvent-based clearing agent. It is the first method for preparing large biological samples for three-dimensional imaging that completely avoids the use of any harmful agents while maintaining fluorescent staining for high-quality imaging.

The new clearing agent unites the speed of an organic solvent with the harmlessness of water-based clarifiers. Tests have shown that the clearing process for a mouse brain, including dehydration, takes 2 days with the new protocol, compared to 10 to 14 days when using water-based protocols. Unlike agents based on organic solvents, the new agent presents no danger from inhaling dangerous fumes or any adverse effects from accidental skin contact. It is less aggressive and therefore much easier to handle in the laboratory and under the microscope than the commonly used organic solvent-based clarifiers. It even naturally occurs in pineapples and is approved as an additive for winemaking.

Optical clearing of tissue samples is an essential process step in sample preparation for light-sheet and ultramicroscopy. One of the key challenges when optically clearing entire organs is the preservation of fluorescent staining that has been performed beforehand. When benchmarking the new clearing medium against alternative methods, it shows excellent fluorescent signal preservation and only a minor impact on the tissue structure, thus satisfying the most important requirements for microscopic analysis of biological samples.

“The new clearing agent is harmless, easy-to-use even for untrained personnel, cost-effective, and already successfully tested in a number of studies,” says Dominik Eckardt, PhD, R&D manager at Miltenyi Biotec. “It holds great promise for a successful commercialization.”

Miltenyi Biotec recently acquired the high-end microscopy specialist LaVision BioTec GmbH, expanding its range of products for cell analysis and preclinical imaging with premium expertise in microscopy. “With the improved clearing protocol, we are now able to set new standards in high-end imaging, further strengthening our portfolio of pioneering analytical tools for biomedical research,” says Eckardt.

The company will initially offer the new clearing agent for neurobiology and cancer research applications. It is expected to play a key role in the study of Alzheimer’s disease and Parkinson’s disease by helping to visualize and quantify plaque formation in mouse brains. Going forward, the company plans to manufacture and market further products based on the newly acquired clearing protocol.

For further information, visit Miltenyi Biotec.

Featured image: Tissues cleared using a new agent and protocol available from Miltenyi Biotec. Image courtesy: LaVision BioTec and Miltenyi Biotec.