A new technique using laser beams could help detect bladder cancer, scientists have said.

Researchers said that the technique, called Raman spectroscopy (RS), which involves shining a light beam on to a sample of tissue to reveal any abnormalities, could be quicker and more reliable than the current biopsy method.

Diagnosis could be made almost instantly while biopsy results can take up to two weeks, they said.

The scientists, from the University of Dundee, examined 14 patients at Ninewells Hospital in Dundee who presented with symptoms of bladder cancer.

Their study, published in Analytical and Biological Chemistry, found that diagnosis made using RS was consistent with the biopsy results in 13 cases.

Dr Ghulam Nabi, lead researcher, suggested that RS has potential to be used to make less-invasive and quicker diagnoses.

He said: "Obviously, the earlier we diagnose cancer, the better the prognosis is for the patient.

"There are some specific difficulties in making a reliable early diagnosis of bladder cancer, and very often it is not diagnosed until the cancer has manifested itself as a variety of symptoms.

"What we have been looking to do is develop an early and reliable diagnosis of urinary bladder cancer. Raman spectroscopy tells us about technical structure of tissue before morphological changes in structure happen as a result of the cancer developing.

"The time that passes between a patient having a biopsy and receiving their results is an extremely anxious one for patients and their families. We believe that RS can remove this anxiety by providing a quick diagnosis and our results so far show that it does indeed show potential as a reliable tool for diagnosis.

"What we need to do now is expand our study population and refine the process until it is as reliable as biopsy but without the negative side-effects."

RS has also been used to discover counterfeit drugs and to investigate the chemical composition of historical documents.