Without proper adherence to both of these principles, the “equal opportunity to be counted once and only once” is not achieved. In addition, stereology uses a 3D disector or counting frame to ensure that each cell in the section thickness is counted only in the area of the section thickness that is not damaged. When you are only examining a single 2D image of a 3D specimen, you cannot identify the unique point, only the number of profiles or cell pieces in the image. Each cell is represented by a unique point – a feature that can only occur in the cell once (like the cell top). Stereology achieves unbiased quantification by providing rules to ensure that each cell has an equal opportunity to be counted once and only once.
Q: If I use imagej to count cells in 2d images, is that biased? This can be achieved by a combination of the feature to be quantified, the tissue preparation or the probe having isotropy. To achieve an unbiased result from stereologic analysis, the probe should interact with the feature to be quantified in an isotropic way. Q: Are you saying that, for any analysis to be possible, it needs to be isotropic? But keep in mind you will only be finding out about the biopsy, not about the whole region. But if you need to quantify it, you can use stereology. What are you trying to find out with the biopsy please? If it is something that you can find out about qualitatively, then there is no need for quantification. Q: I just wanted to add, about lung sterology, that we use small human lung biopsies about 2mm to be cut at 2 µ m. Yes, it is relevant for any biological tissue you are viewing under the microscope. Q: Is the information presented in this webinar relevant for lung stereology?