Define the counting frame size

Optical Fractionator - step 6

Counting Frame Display

Force the counting frame to be square: Change the shape of the frame to a square.

Snap to increments of: Use if you want the size of the counting frame size to be rounded; a counting frame size set as a whole number is easier to remember and to apply to future experiments.

Counting Frame Size

Size the counting frame to fit approximately 5 objects of interest.

1. Choose a unique identifying point that only comes into focus once for your cell such as:
   • Cell top
   • Nucleus top
   • Nucleolus (unless there are multiple nucleoli in your cells of interest)
2. Adjust the counting frame until it is approximately large enough to have, on average, 1 to 5 objects.

 

Some counting frames may have 0 objects, or more than 5 – this is completely acceptable. The reason for so few cells per counting frame is 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, hover the cursor over the counting frame, drag the mouse to move the frame.

Verify that:

• The counting frame is in the center of the screen.
• There is a large enough border around the outside of the counting frame so that you can clearly distinguish objects that are on the edge of the counting frame.
• The tails of the counting frame are visible.