The FINANCIAL — IBM scientists have developed a flexible, non-contact microfluidic probe made from silicon that can aid researchers and pathologists to investigate critical tissue samples accurately for drug discovery and disease diagnostics, according to IBM.
Tissue staining is widely used in pathology to detect disease markers in a patient's sample. More specifically, a particular disease marker is bound with an antibody, which is then chemically colored or stained on the tissue. The intensity of the color classifies and determines the extent of a disease.
Tissue staining is a tedious process with many chemical steps analogous to developing photographs, whereby excessive chemical solution or long exposures can overdevelop the sample or photograph. In the context of pathology, this can cause false positives and negatives, which can lead to misdiagnosis. According to a report issued by Johns Hopkins Hospital, of 6,171 biopsy slides that were sent from late 2008 for a second review, pathologists disagreed with the diagnosis on 86 of them.
Obtaining a biopsy is an invasive procedure for the patient, so small samples are taken whenever possible. Pathologists are determined to gain as much information as possible from these small samples, which can be only a few millimeters in length. Working at this scale requires staining to be performed on many thin slices of the sample to identify and sub-type diseases such as cancer, for treatment.
Pathologists are often challenged in performing a sufficient number of important tests on these limited samples, critical for personalized treatment strategies.To address these important challenges, IBM scientists in Zurich are reporting today in the peer-reviewed journal Lab on a Chip an innovative proof-of-concept technology called the microfluidic probe, which can accurately stain tissue sections at the micrometer scale.
The eight millimeter-wide, diamond-shaped probe consists of a silicon microfluidic head with two microchannels at each tip. Similar to an inkjet printer cartridge, the head injects the liquid on the surface, but then unlike a printer, it continuously aspirates the liquid to prevent spreading and accumulation on the surface, which can lead to overexposure.
Specifically for tissue section analysis, the probe can deliver an antibody very locally in a selected area of a tissue section with pinpoint accuracy. Since analysis can be done on spots and lines instead of on the entire tissue section, the tissue is better preserved for additional tests, if required. In addition, only a few picoliters of liquid containing antibodies are needed for each analysis spot.
This research is based on IBM's decades of experience with silicon, which is now being applied to novel micro and nanotechnologies to solve today's greatest challenges ranging from energy production and consumption to healthcare.
The microfluidic probe fits to standard workflows in conventional pathology. In addition, it is compatible with current biochemical staining systems and is resistant to a broad range of chemicals. The small size of the probe also enables easy viewing of the sample from above and below by an inverted microscope commonly used in research and clinical laboratories.
IBM scientists will continue to test and improve the probe and potentially begin using it in laboratory environments in the next several months. In addition, the team plans to explore specific clinical applications, possibly with partners in the field of pathology. The microfluidic probe promises to support the work of pathologists and become a tool of choice for pharmaceutical research and diagnostics involving biological specimens.