FAQ 12: Can I sample several different populations simultaneously?

It depends greatly on how these different cell populations are distributed within the region of interest. If they share a similar distribution, then it’s likely that they can be counted simultaneously by simply using different markings to count the different cell types. However, if there is a difference in how they are distributed, then they may need to be counted separately using different sampling parameters. These differences may include (but are not limited to):

  • The approximate number of cells found in the region of interest
  • How uniformly they are distributed throughout the region of interest (i.e. are they found in clusters, or are they evenly scattered?)
  • Whether the distribution appears to change as a function of an anatomical axis (i.e. do more appear in the caudal portion of the region of interest, or do they appear in similar numbers in all sections?)

There have been recent developments that expand the capabilities of an Optical Fractionator probe, and the “Double Disector” method may prove useful if your cell populations are too different to be counted using the same sampling parameters, but are similar enough that the parameters differ by only 100-200%. The “Double Disector” is a modification of the disector that is used in the Optical Fractionator whereby a small grid of counting frames appears on the screen, but the cell populations are counted differently. One cell population will be counted using only one of the counting frames (typically the more homogeneously distributed population), while another cell population will be counted using all counting frames.

This FAQ comes from stereology.info, our curated collection of information and references regarding the use of stereology in the biological sciences. Feel free to review the other FAQs there as well. We hope this thread will spark some in-depth discussion on stereology!