Virtual cycloids allow users to quantify surface area and surface density of biological objects without the need to rotate tissue prior to sectioning (Gokhale et al., 2004).
Like the closely related Space Balls® probe (Mouton et al., 2002), the virtual cycloid probe is isotropic. Thus, biological objects can be quantified on tissue sections cut at any convenient orientation, e.g., coronal, sagittal.
The figure below shows the orientation of a virtual cycloid with minor axis parallel to the focusing direction in the z-axis (as indicated by arrow pointing in vertical axis). Users simply focus through the z-axis and click when the point intersects the object boundary, e.g., cell membrane; I = probe-surface intersections.
Because multiple vertical planes can be sampled in the same section, the virtual cycloid probe is not only unbiased but far more efficient than any other approach for quantifying surface area.
The Stereologer is the only commercially available stereology system with both the Virtual Cycloids and Space Balls approaches.
- Mouton PR, Gokhale AM, Ward NL, West MJ. Stereological Length Estimation Using Spherical Probes. J Microsc 206: 54-64, 2002.
- Gokhale AM, Evans RE, Mackes JL, Mouton PR. Stereological Estimation Of Surface Area In Thick Transparent Sections Of Arbitrary Orientation Using Virtual Cycloids. J Microscopy 216: 25-31, 2004.