Purdue University researchers say they've developed new technology for cancer detection that eliminates the need for drawing blood.

The technology allows physicians to detect and count circulating cancer cells, such as those on the wrist or the inside of the cheek, by shining a laser on surface veins.

Purdue researchers collaborated with cancer and biotechnology experts from the Mayo Clinic to develop the technology.

In addition to being less invasive, the new detection method is able to evaluate a much larger volume of blood than what can be drawn from a patient for analysis, said Philip Low, Purdue's Ralph C. Corley distinguished professor of chemistry, in a news release.

"In the initial stages of cancer, there are very few circulating tumor cells — cells that indicate the spread of cancer and initiate secondary tumor formation," Low said.

"By increasing the volume of blood analyzed, we improve the sensitivity of the test and allow for earlier diagnosis. If there are two cancer cells in every 50 milliliters of blood, odds are the cells would not be found in a 10-milliliter blood sample. However, the cells would be found in the 100 milliliters of blood that flow through large veins each minute."

The technique could provide doctors and patients results in a matter of minutes and save the medical industry millions of dollars in testing equipment, said Wei He, a graduate student in Purdue's Department of Chemistry and the Department of Biomedical Engineering.

By directly labeling tumor cells while they are in the bloodstream, some of the costs and problems associated with testing drawn blood samples can be avoided, Wei said.

"One sample can require five to 10 test tubes during the course of sampling, processing and analysis such as handling, labeling and washing," he said. "In addition, large hospitals can have more than 300 cancer patients in one day. Such a large influx can cause delays in sample processing and delays can affect the results of analysis."

A paper detailing the technology and detection technique was published in the July 10 Proceedings of the National Academy of Sciences.