Researchers Unveil Surface Sampling Probe for Intraoperative Biopsies

The Oak Ridge National Laboratory, known best for nuclear weapons research, has developed a surface sampling probe that may replace professional pathologists in identifying cancerous tissue during surgeries. Currently, samples are taken to the pathology lab to confirm that all of the cancer has been removed. This takes considerable time, extended by the preparation process necessary before the pathologist looks into the microscope. The new probe hopes to do the same, but right inside the operating room and without requiring a pathologist to operate.

The device uses a droplet-based mass spectrometry technique that is able to spot even large biomolecules such as proteins, a capability other mass spectrometry methods have not been able to achieve. So far the device has been able to identify drugs and certain metabolites in animal tissue, hopefully soon moving on to trials with human samples.

Described here are the results from the profiling of the proteins arginine vasopressin (AVP) and adrenocorticotropic hormone (ACTH) from normal human pituitary gland and pituitary adenoma tissue sections, using a fully automated droplet-based liquid-microjunction surface-sampling-HPLC–ESI-MS–MS system for spatially resolved sampling, HPLC separation, and mass spectrometric detection. Excellent correlation was found between the protein distribution data obtained with this method and data obtained with matrix-assisted laser desorption/ionization (MALDI) chemical imaging analyses of serial sections of the same tissue. The protein distributions correlated with the visible anatomic pattern of the pituitary gland. AVP was most abundant in the posterior pituitary gland region (neurohypophysis), and ATCH was dominant in the anterior pituitary gland region (adenohypophysis). The relative amounts of AVP and ACTH sampled from a series of ACTH-secreting and non-secreting pituitary adenomas correlated with histopathological evaluation.