Researchers at UCLA along with the National Institute of Dental and Craniofacial Research have developed a novel salivary sensor, based on a confocal microscope, that can detect the presence of certain proteins that are markers for cancer and perhaps other disorders.
From a press release:
The sensor can be integrated into a specially designed lab-on-a-chip, or microchip assay, and preprogrammed to bind a specific protein of interest, generating a sustained fluorescent signal as the molecules attach. A microscope then reads the intensity of the fluorescent light – a measure of the protein’s cumulative concentration in the saliva sample – and scientists gauge whether it corresponds with levels linked to developing disease.
In their initial experiments, the scientists primed the optical protein sensor to detect the IL-8 protein, which at higher than normal concentration in saliva is linked to oral cancer. Using saliva samples from 20 people – half healthy, the others diagnosed with oral cancer – the sensor correctly distinguished in all cases between health and disease.
Importantly, the sensor achieved a limit of detection for IL-8 that is roughly 100 times more sensitive than today’s blood-based Enzyme-Linked ImmunoSorbent Assay (ELISA) tests, the standard technique to measure protein in bodily fluid. The limit of detection, or LOD, refers to a sensor’s ability to distinguish the lowest concentration of a protein or other target molecule apart from competing background signals.