ST. LOUIS, Feb. 12, 2013 /PRNewswire/ -- Sigma-Aldrich® Corporation (NASDAQ: SIAL), a leading Life Science and High Technology Company, announced that Sigma ® Life Science, its innovative biological products and services business, signed an agreement to distribute worldwide Olink Bioscience's Duolink ® In Situ products, which present a new disruptive method for imaging and measuring protein-protein interactions in unmodified cells. The Duolink In Situ products work in tandem with Sigma Life Science's broad antibody portfolio and will allow researchers to target the precise protein of interest and enable robust analyses and imaging. For more information, visit www.sigma.com/duolink. The versatile technology, among other applications, can be used in combination with CompoZr ® Zinc Finger Nuclease-mediated gene editing to track knocked-out or knocked-in genes and with MISSION ® RNA interference technologies to track protein expression following gene knockdown. "The synergy between Olink and Sigma Life Science's global support network will help the scientific community to access and to accelerate the adoption of the powerful Duolink technology," said Josef Zihlmann, Vice President at Sigma Life Science. The proprietary PLA ® technology allows Olink's Duolink In Situ products to quickly image the locations of single protein-protein interactions regardless of strength, measure protein expression levels, and identify relative changes in post-translational modification events. The technique relies upon two target-specific primary antibodies, a "plus" and "minus" pair of species-specific PLA probes conjugated to DNA oligos that—when a target pair of proteins are in close proximity—can hybridize to trigger a rolling circle amplification reaction. Fluorescent detection probes bind the several hundred-fold amplified DNA at high density, allowing visualization of single protein–protein interactions inside an intact cell using a standard fluorescence microscope. "The ability to visualize these protein-protein interactions in unmodified cells under endogenous expression and at very low levels is a fundamental advance that allows greater insight into basic biology, pathways, spatial phenomena and potential therapeutic targets in those pathways," said Zihlmann.