Account for missing section

Purpose

The issue of missing sections occurs regularly in biological work. Sections are damaged during processing or mounting and, as a result, are not available for stereological use.

Options for accounting for a missing section

Option 1 Randomly choose another starting section among the other possible starting points so that the missing or damaged section will not be needed.
Option 2

Substitute a neighboring section (that was not going to be included in the sampling) for the missing section if:

  • The Evaluation Interval is greater than one...

AND

  • ... There is reasonable evidence to suggest that there are no significant changes from one section to the next (substantial differences between neighboring sections could dramatically alter the results).
Option 3

Simulate the probe for that section by marking down the number of cells if:

  • The mean number of particles for the two adjacent sections (to the missing section) seems to be the appropriate approximation for the number of particles on the missing section.
Option 4

Use the Account for Missing Section tool in Stereo Investigator if:

  • You have one contour per section.
  • Cavalieri probe: The mean of the sections counts for the section before and the section after the missing section seems to be an appropriate estimation for the missing section.
  • Fractionator/Optical Fractionator probe: The mean of all the section counts is an appropriate estimation for the missing section.

Procedure

  1. Create a placeholder section for the missing section with the Serial Section Manager. Draw a closed contour in that section.
  2. Click the Account for missing section button on the Probes ribbon, Stereology results section.
    1. Select the type of probe: Fractionator, Optical Fractionator, or Cavalieri.
    2. In the list of missing sections, select the placeholder section created in step 1. Click OK.
  3. When viewing the results of the probe, two types of results are displayed:
    • Estimated total by [probe name]: Estimate with the missing section.
    • Missing section corrected total by cavalieri: Estimate using the mean of the section counts for the section before and the section after the missing section substituted in for the missing section.
    • Missing section corrected total by fractionator: Estimate using the mean of all the other section counts substituted in for the missing section

 

Use a different methodology if you are counting multiple contours per section AND only one of the regions in the section is missing (not the entire section).