It looks like an elongated blob: a pulsating, concave blob, suspended on wires. It doesn’t seem like much when I first see it in the flesh–except that it may represent the future of drug testing.

I’m standing in the lab at Tara Biosystems, a startup near the East River, in New York City. CEO Misti Ushio is showing me around the newly opened space. As I look through a microscope, the blob, which is made of artificially created heart tissue, starts to jiggle in response to an electric current. It’s like a real heart reacting to stimulus from the brain: pumping and pumping. It’s just a lot smaller than a real human heart–about 3 millimeters long in its non-magnified version.

Tara, a three-year-old company spun out of research at Columbia University, grows the tissue from stem cells, nurturing them for up to 12 weeks. It then tests the tissue’s reaction to various drug compounds, demonstrating how real human hearts may react in the real world. Drug companies are already using the platform as an alternative to petri dishes of heart cells, or mice and pigs that stand in (often poorly) for humans. Some startups refer to their people as the beating heart of their operations. Tara’s beating heart really is its beating heart.

“It’s like a tissue machine,” says Ushio. “We have a pipeline at different stages of development, so we’re always ready if we need to do a study and we can react quickly.” The lab’s fridge contains about 200 tissue cultures at any one time, she says.

Tara currently does mostly toxicology testing with the platform–that is, making sure that the heart tissue isn’t harmed when it’s bathed in a drug solution. That offers an early-stage warning system for pharma companies. Instead of waiting for human trials at the end of the drug development process to reveal toxicology problems, they can now see if there could be problems before real humans are ever involved. More than 10 drug groups are already using Tara’s service, Ushio says (she won’t name names as yet).

“Over the summer we began to get to a stage where we didn’t really have to convince people why this is important. They know why it’s important. They just want us to demonstrate that we can do it.”

The mini heart scaffold can test for electrical, chemical, mechanical, structural, and biological (gene expression) effects of drugs. And it’s been proven, Ushio says, for 40 different compounds against results produced by more conventional testing methods.