Jonathan Beard reports in New York that people suspected of ulcers can get the test results in a few minutes without leaving the doctor's surgery, thanks to an instrument that can detect the proportion of carbon isotopes in their breathing.
According to its inventor, Daniel munick of Rutgers University, this new device based on carbon dioxide lasers is as accurate and sensitive as laboratory instruments costing tens of thousands of dollars, New Jersey.
Instruments developed by Murnick and Brian Peer, working with him as an undergraduate assistant, can compare the proportions of two isotopes of carbon12 and carbon-
13-in the gas sample
Murnick explained that we used a carbon dioxide laser to illuminate the sample gas.
Under the laser stimulation of the correct wavelength, carbon dioxide molecules change their excitation state in the discharge, resulting in electrical signals.
Different signals of carbon dioxide containing these two carbon isotopes were obtained.
The instrument measures the ratio of two signals to determine carbon-
Contains in the sample.
Murnick says the instrument can detect ulcers in a simple test.
Take a small amount of urea for the patient (CO(NH2)2)
Carbon contains stable non-radioactive isotope carbon-13.
Hp is a bacteria that is often lurking in the stomach and is known to be the cause of many ulcers, which can metabolize urea in the stomach, resulting in the production of carbon dioxide.
In the uninfected stomach, urea is not broken down and delivered to the intestines.
In the diagnostic test, the patient obtained the sample and, 20 to 40 minutes later, entered the Tube by breathing out and gave a sample of their breath.
Carbon atoms account for only 1 of them.
If the laser device detects a spike in carbon
In the sample, there is evidence that the person was infected with H. pylori.
Murnicks says the bacteria have been metabolizing urea for many years.
Previous tests sometimes used urea labeled with radioactive carbon.
As a result, these patients are exposed to radiation hazards and produce radioactive waste. If carbon-
13 for marking urea, an expensive laboratory mass spectrometer is required to detect urea.
A Medical Instrument Company in New Jersey, diagnostics and equipment, approved Murnick's idea and plans to make an early version next year.
Murnick says detecting ulcers is just one of many possible applications of a fast, inexpensive method for determining isotope ratios: "Many other medical conditions involving the liver, colon, and other organs can pass this
For example, we can label glucose, lactose, or caffeine with carbon
Monitor the carbon dioxide emitted by the patient.
Pollution control is another area where sensitive testing equipment is needed.
For example, scientists now use spectra to check the levels of contaminants in water to compare the isotope ratios in multi-chlorine hydrocarbons.
The instruments based on our technology should be cheap, small enough for research ships and vans, Murnick said.