Department of Physical Therapy and Rehabilitation Science

A New Model for Volume Quantification of Isolated Pancreatic Islets

Islets of Langerhans (islets) are spherical-like clusters of endocrine cells that have a large range of sizes from 20µm to more than 400µm in diameter both in rodent and humans. Therefore, an accurate and consistent method to quantify the amount of tissue being used in experiments is of crucial relevance for islet research and transplantation. Our research group developed and tested a new easy-to-use Kansas Method to quantify islet volume with greater accuracy. In order to improve islet volume calculations, we are freely distributing this new Kansas Method for clinicians and researchers. The spreadsheet automatically calculates cell number from the measured islet diameter. Download it here

Currently, islet equivalent (IE), the standard estimate of isolated islet volume is the most common measurement used both in the clinic and in the laboratory. However, the accuracy of the IE measurement has been challenged for years, because the IE calculations are based on the assumption that all islets are spherical; an assumption that has already been shown to be incorrect. In reality, most islets are disk-shaped oblate ellipsoids or irregular shaped, especially in culture. Therefore, using IE calculations may create errors in volume quantification.

Here, we developed and tested a new method for estimating islet volume based on cell number counts. We completed validity and reliability studies on our new method and showed that it is a fast and more accurate and reliable method of estimating rat islet volume. These efforts are relevant to improving the accuracy of transplanted tissue volume, and assuring that erroneous results are not reported in the literature.