Isolation of Hepatocytes from Liver Tissue by a Novel, Semi-Automated Perfusion Technology.

Primary hepatocytes are a major tool in biomedical research. However, obtaining high yields of variable hepatocytes is technically challenging. Most protocols rely on the two-step collagenase perfusion protocol introduced by Per Ottar Seglen in 1976. In this procedure, the liver is perfused in situ with a recirculating, constant volume of calcium-free buffer, which is maintained at 37 °C and continuously oxygenated. In a second step, the liver is removed from the carcass and perfused with a collagenase solution in order to dissociate the extracellular matrix of the liver and liberate individual cells. Finally, the dissected hepatocytes are further purified and concentrated by density-based centrifugation. However, failure in proper cannulation, incomplete enzymatic digestion or over-digestion can result in low cell yield and viability. Here we present a novel semi-automated perfusion device, which allows gentle, rapid and efficient generation of a single-cell suspension from rodent livers. In combination with prefabricated buffers, the system allows reliable and highly reproducible isolation of primary hepatocytes.

A novel device for collecting and dispensing fingerstick blood for point of care testing.

The increased world-wide availability of point-of-care (POC) tests utilizing fingerstick blood has led to testing scenarios in which multiple separate fingersticks are performed during a single patient encounter, generating cumulative discomfort and reducing testing efficiency. We have developed a device capable of a) collection of up to 100 µL of fingerstick blood from a single fingerstick by capillary action, and b) dispensing this blood in variable increments set by the user. We tested the prototype device both in a controlled laboratory setting and in a fingerstick study involving naive device users, and found it to have accuracy and precision similar to a conventional pipettor. The users also found the device to be easy to use, and recommended minor ergonomic improvements. Our device would allow performance of multiple POC tests from a single fingerstick blood sample, thus providing a novel functionality that may be of use in many testing settings worldwide.