Thermal Gradient device could make it easier to get treatment to millions of AIDS victims.


Rochester biotech startup Thermal Gradient says it has invented a device that could make it easier to get treatment to millions of AIDS victims in underdeveloped parts of the world and provide early warning of an attack by an airborne biological weapon.

The new technology reduces the time needed to perform DNA testing from hours to minutes, said Bob Juncosa, Thermal Gradient's chief technology officer.

Thermal Gradient was started by Juncosa and Joel Grover, chief executive officer. Both were managers at Ortho-Clinical Diagnostics until 2004, when they were laid off. Since 2008, Thermal Gradient has been a tenant of the biotechnology business incubator funded by the University of Rochester Medical Center and New York state.

The company recently signed an agreement with Axela Inc., a Toronto company, to use Thermal Gradient's technology in a new diagnostic system to be made by Axela.

DNA-based diagnostic testing is not done routinely because it is expensive and time consuming. DNA tests can take hours, whereas traditional chemistry tests can be done in seconds. But DNA tests are much more sensitive.

Non-DNA tests search for evidence of a body's response to an infection. DNA testing can isolate the DNA of the source of the infection and detect that invasion much earlier, possibly even before the body has time to respond.

To find the DNA of an invading force, that DNA often must be "amplified" to make it detectable. That is done by heating and cooling the sample repeatedly, something called polymerase chain reaction (PCR). Each time the temperature of the sample is raised and lowered, the amount of DNA is doubled. Eventually it grows enough to make it detectable.

The PCR process now can take between 50 minutes and two hours. With the Thermal Gradient method it can be done in four to eight minutes.

"What Thermal Gradient has invented is a method by which you do that PCR step much faster and in a much simpler device, and it's so inexpensive it's disposable," said Juncosa.

The Thermal Gradient device doesn't raise and lower the temperature of the container; it pumps the sample through tiny channels so that it very quickly passes from a hot side to a cool one over and over.

The cost of the Thermal Gradient component will vary depending on the exact application in which it's used, but its low cost is a major advantage. If produced in large volumes, the cost of the device would be less than $1 each, Juncosa said.

Thermal Gradient's device, a component of a larger DNA testing system, has been built in a variety of shapes and sizes comparable to a thick postage stamp and even smaller than a sugar cube. The smallest versions are designed for devices that can be placed in public areas, such as train stations or airport terminals. The device would "sniff" the air to detect airborne pathogens.

With National Institutes of Health funding, Thermal Gradient has developed a thumb-sized cartridge for use in a portable shoebox-sized DNA testing machine. With the machine, workers from the World Health Organization and other agencies can visit out-of-the-way places in underdeveloped parts of the world and test for HIV or AIDS on site. Such samples now must be taken to labs in other places. By the time the results are known, the infected patients often cannot be located.

With Thermal Gradient's invention, DNA testing can even be done while a patient waits on an operating table.

"There are situations where you want to determine whether a growth is cancerous, so you can take the tissue and you could run it on a system like this, and a half-hour or 15 minutes later you know whether that material is cancerous," Juncosa said. "Otherwise, you have to seal the patient up, or keep them open for a lot longer period of time while this test is being run.

"Nobody in the world can do PCR faster than we can because of the design of these devices," Juncosa said.

Thermal Gradient's goal is to be the core piece for a larger company that makes DNA testing systems.

"Our business model is we want to be the Intel of nucleic acid testing," Juncosa said.

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