Innovation, influence and business in America's medical cities.

MADISON, Wisconsin — Another day, another dollar — or rather a few million dollars — for pluripotent stem cell company Cellular Dynamics International Inc.

After filing a regulatory document last week with the Securities and Exchange Commission stating it had raised $31 million, the Wisconsin company amended the filing. The company now says it has raised $40.6 million in equity, according to a new document.

The company hasn’t said anything publicly about fundraising — in press release form, at least — since November 2008, when it said it had closed an $18 million Series A round. That round was led by Northbrook, Ill.-based Tactics II Stem Cell Ventures LP.

Further details are tough to come by since Cellular Dynamics Communications Director Joleen Rau and Tactics II didn’t respond to inquiries made last week. Rau also didn’t respond Friday to a voicemail.

The company specializes in pluripotent stem cells, which can differentiate into any cell type for use in drug development.

Cellular Dynamics in December launched its first product, iCell Cardiomyocytes, human heart cells designed to aid drug discovery and improve the predictability of drug compounds, according to a statement from the company. The company takes cells from a patient’s own blood or other tissue and chemically reverses them back to a pluripotent state.

Researchers can use the cells to study a range of areas, including toxicity of new or existing drugs, to the electrodynamics of both healthy and diseased cardiac cells.