Assessment of collagen fibril spacing in relation to selected region of interest (ROI) on electron micrographs—application to the mammalian corneal stroma

Abstract

Selection of an ROI for assessment of packing density and interfibril distances should be standardized for comparative assessments of TEMs of collagen fibrils.

Age-related dataset on the mechanical properties and collagen fibril structure of tendons from a murine model

“…To determine ρ, the cross section of each fibril (or part fibril at the image boundary) was manually traced, and the area, a f , of individual fibril was computed using the image analysis package. The value of ρ was computed as the ratio of the sum of a f s values to the total sample area 33 . For the measurement of D, following a common approach that has been reported elsewhere 31 , 34 D was derived from the a f by modelling the shape of the fibril as circular.…”

Averaged Spacing and 2-D Organization of Collagen Fibrils in the Posterior Cornea of the Rabbit Eye Assessed by Transmission Electron Microscopy

“…As detailed previously, these images were then projected onto a vertical white screen ( Figure 1) to obtain a final magnification of close to 250,000X and an overlay prepared by drawing the outlines of the fibrils onto one or more sheets of A3-sized white paper (42 Â 29.5 cm). 14,26 If there was any interfibrillar (stained) material (e.g. see upper left of Figures 1 and 2A), this was ignored and just the fibrils outlined.…”

“…Sections were stained by exposure to 2% phosphotungstic acid (in water) at RT for 1 h and then examined using a FEI Morgagni 268 transmission electron microscope operating at 60 kV. 14 …”

“…5,14 The objective of the present study was to assess whether or not there can be consistency in the 2-D organization of corneal stroma fibrils by applying the same sampling strategy and analysis to a set of micrographs rather than different methods applied to individual examples. 5,14 This was done by taking a representative set of micrographs from carefully matched rabbits with the same region of the corneal stroma being selected for analysis. Therefore, for the first time, a set of pooled data was obtained to allow for assessment of the inter-fibril spacing in the stroma as based on nearest neighbor distances as well as the nearest neighbors peak profile in 2-D radial distribution functions.…”

“…5,[10][11][12][13][14] This twodimensional (2-D) descriptor of the organization of collagen fibrils in the cornea can be expected to show a dominant first peak that has been referred to as the nearest neighbors distance. 10 Indirectly, this issue of inter-fibril spacing in the corneal stroma has been considered in other ways as well.…”