ESTIMATING SURFACE-AREA BY THE ISOTROPIC FAKIR METHOD FROM THICK SLICES CUT IN AN ARBITRARY DIRECTION

The proposed fakir method for estimating surface area is based on coun ting the intersections between the surface lying within a thick slice, and an isotropic spatial grid consisting of a combination of linear p robes called fakir probes. An unbiased procedure using a directly rand omized spatial grid rather than sections with randomized directions is presented. The method is applicable if perfectly registered serial se ctions of the surface are a available in a, thick slice while the dire ction of the slice can be arbitrary The efficiency of the fakir method using different arrangements of orthogonal triplets of fakir probes i s evaluated and it is shown that mutually shifted probes are superior to nonshifted ones. The application software for interactive counting of intersections between computer-generated fakir probes and the surfa ce within the stack of digitized images is described and demonstrated by two examples: estimation of the surface area of individual tobacco cell chains using a confocal microscope, and estimation of the total a rea of exposed surface of mesophyll cells in a barley leaf using a wid e-field transmission microscope.