3M is making its largest acquisition ever, as measured by price. The Maplewood-based manufacturer has agreed to pay 850 million dollars in cash to buy a lens-making operation from the glass and fiber optics-maker Corning. Analysts say the deal marks a departure for a company not known for big acquisitions. They also say 3M is taking advantage of its financial strength to get a bargain. Minnesota Public Radio's Andrew Haeg reports.