Accuri Cytometers is scrambling to meet steep demand for its revolutionary cell analysis product.

The firm, which hauled in $13 million in venture capital just last year, secured another $4 million this month to expand its production capabilities. The deal will allow the medical device company to satisfy its client base and continue its expansion. "It's a great time to be able to actually get funding and it's really fundamentally about enabling the growth of the company," CEO Jenn Baird told me. "We're growing so rapidly that we need the working capital and the growth capital to accomplish that growth."

The firm's flow cytometry system has found a welcome audience among biomedical researchers. Baird said sales have "more than doubled" since 2008, when the product was introduced, although she wouldn't provide specifics.

Accuri's latest funding round included participation from Ann Arbor-based Arboretum Ventures and state-managed InvestMichigan Growth Capital program. Arboretum's continued faith in Accuri comes as fund managers Jan Garfinkle and Tim Petersen have guided Arboretum to the role of Michigan's most watched venture capital firm.

The investors' faith in the intrinsic value of Accuri's flow cytometry product trumped any skittishness about investing in a challenging financial environment.

"Current investors welcomed the opportunity to provide additional capital to help fuel the company's accelerating growth," said Harry Wilcox, a partner at Flagship Ventures, one of the funding participants, in a news release.

The funding comes a year after Accuri secured $13 million in capital from several sources. That funding allowed the firm this year to introduce a new product called CSampler, an accessory to the flow cytometer that further automates the data collection process and allows researchers to avoid errors.

The participants in Accuri's latest funding round were: Fidelity Biosciences, Flagship Ventures, Baird Venture Partners, Arboretum and Credit Suisse-managed InvestMichigan, which is investing state pension fund money in an attempt to spur economic development and reap returns for pension holders.

Baird said the firm would continue to add employees, but she said specific personnel goals would depend on the firm's sales trajectory. She said Accuri has 60 employees worldwide, including 42 in Michigan.

"We really are just trying to ramp up production rates to meet the strong demand from our customers," Baird said. "It's all about meeting demand in the marketplace."