Detecting radiation exposure is a time-consuming and expensive procedure, with conventional blood-based tests costing thousands of dollars and taking days before results come out.

A small Los Angeles-based company hopes to revolutionize the process.

According to CEO of DxTerity Diagnostics Bob Terbrueggen, the company’s DxDirect technology represents an opportunity to lower testing costs, and to improve the way the authorities deal with incidents where a large number of people are exposed to radiation.

DxTerity Diagnostics’ system uses a relatively simple method to detect the level of expression of certain genes, and does not require new equipment.

The technology uses small strings of DNA that bind to the RNA produced from the target gene. When the target is detected, the probes form a larger segment that can be detected using capillary electrophoresis. Introduced in the 1960s, capillary electrophoresis separates molecules according to their size-to-charge ratio.

Applying the technology to genes whose activity responds to radiation exposure, the company developed the Radiation Exposure Dosage Index-Dx, or REDI-Dx, that will become available in the U.S. early next year. 

“Current tests sell for about $3,000. Our technology allows it to be done for a hundredfold less, so for about $30,” Terbrueggen said.

“What we are able to do uniquely better than others is that we don’t use a marker but a panel of markers. In the case of the radiation exposure test, the current version is that we use 15 genes to calculate the level of exposure,” Terbruggen said.

The 15 genes used as markers were selected in collaboration with Duke University whose researchers studied cancer patients undergoing radiotherapy to determine which genes were expressed more than usual specifically in response to radiation.

Terbruggen said that in addition to being affordable, the REDI-Dx can produce results within three hours when blood samples are taken more than six hours after they are first exposed to radiation.

“In the Chernobyl incident, the biggest (causes) of death (were) suicide, depression and alcoholism because people didn’t know. We can tell people quickly whether they have anything to worry about in the short term,” he said.

“The test was designed to work out who is okay, so the medical personnel can concentrate on those who really need their help.”

While Terbruggen is looking for collaborators in Korea and other nations to test the REDI-Dx, his company is also working on tests based on the DxDirect technique for detecting other conditions that accompany changes in gene expression.

“Think of DxDirect as an operating system: You have a way of running things and you put in different software for different applications,” he said.

“In general the Direct DX platform allows us to do a broad range of tests. We are working on a colon cancer test that can diagnose colon cancer with a drop of blood, we are working on a cardiovascular test and we are also working on a test for sepsis,” Terbrueggen said. Sepsis is a condition that occurs when a patient develops an infection after undergoing surgery, and according to Terbrueggen the condition has a fatality rate of 25 percent.

“We are working on tests that allow doctors to figure out what is going on in a person’s body with a drop of blood so that they can treat them better.”

By Choi He-suk  (cheesuk@heraldcorp.com)