Physical Fractionator workflow >

5. Define the counting frame size

Counting Frame Display

  • Force the counting frame to be square: When selected, it is implemented as you adjust the size.
  • Snap to increments of: Use if you want the size of the counting frame size to be rounded; it is easier to remember a counting frame size set as a whole number for use in future experiments.

Counting Frame Size

In subsequent steps, you will need to determine if the objects of interest (e.g., cell cross sections) are present or absent in the reference and in the lookup sections.

  • Size the counting frame to fit a manageable number of objects of interest.
  • 2 to 8 objects are much easier to work with than 20 to 80 objects.
  • This may or may not be possible depending on the homogeneity of the distribution of the objects.

 

Some counting frames may have no objects or many objects; this is completely acceptable. We recommend setting the counting frame size to include, on average, a small number of objects to minimize user error and fatigue.
As you focus through the tissue to mark cells, it may be easy to lose track if you try to observe too many cells especially in dense populations.

To move the counting frame’s location on the screen, drag it with the mouse.

Make sure that:

  • You place the counting frame in the center of the screen
  • There is enough space around the outside of the counting frame to clearly distinguish objects that are on the edge of the counting frame.
  • The tails of the counting frame are visible.