Three acquisitions in the past year have helped drive up costs and profits at Minneapolis biotech-testing supply company Bio-Techne.

Bio-Techne, in northeast Minneapolis, saw earnings rise 31 percent to 89 cents per share in the quarter ended Dec. 31, based on revenue of $112 million, according to quarterly results reported Tuesday. Adjusted earnings per share of 82 cents fell 4 cents short of analysts' estimates.

President and CEO Chuck Kummeth noted in a news release that despite currency-exchange challenges, the company posted "exceptional" sales growth of 27 percent in China over the same quarter last year. The company's biotechnology segment, its largest division, had an adjusted operating margin of 50 percent, which was a slight decrease on $78 million in net sales.

Bio-Techne's quarterly operating expenses have nearly doubled since this time last year, to $41 million, while net earnings have risen 32 ­percent, to $33 million.

Bio-Techne continues to integrate the operations of three companies it has ­purchased in the past year: CyVek on Nov. 4, ProteinSimple on July 31, and Novus Biologicals on July 1. The company is planning a full-scale commercial launch this quarter of Ella, its rebranded immunoassay testing platform using CyVek's CyPlex technology.

Bio-Techne, which recently changed its name from Techne Corp., had $358 million in net sales last year of its tools and bioactive compounds used by researchers and medical technicians for drug-discovery and clinical testing.

The company's shares closed at $90.25 Tuesday, down $2.81 on the day, or 3 percent.

Twitter: @_JoeCarlson