Confocal microscopy 3D imaging of diesel particulate matter

Abstract

To date, diesel particulate matter (DPM) has been described as aggregates of spherule particles with a smooth appearing surface. We have used a new colour confocal microscope imaging method to study the 3D shape of diesel particulate matter (DPM); we observed that the particles can have sharp jagged appearing edges and consistent with these findings, 2D light microscopy demonstrated that DPM adheres to human lung epithelial cells. Importantly, the slide preparation and confocal microscopy method applied avoids possible alteration to the particles’ surfaces and enables colour 3D visualisation of the particles. From twenty-one PM10 particles, the mean (standard deviation) major axis length was 5.6 (2.25) μm with corresponding values for the minor axis length of 3.8 (1.25) μm. These new findings may help explain why air pollution particulate matter (PM) has the ability to infiltrate human airway cells, potentially leading to respiratory tract, cardiovascular and neurological disease.

3D Imaging of Roadside and Underground Railway Particulate Matter Structures

“…In order to investigate whether the shapes of particles could be affected by the slide preparation technique, we also prepared slides for confocal microscopy using double-sided adhesive tabs used in scanning electron microscopy in a similar fashion to that we have previously described in a diesel particulate matter imaging study. 11 In essence, the steps were as follows: a piece of filter paper was placed in a plastic Petri dish with a lid. A sample of the underground railway PM was sprinkled on the filter paper using a small spatula and the lid replaced.…”

“…Previous studies of PM have mostly used 2D light microscopy, scanning electron microscopy (SEM), or transmission electron microscopy (TEM). However, 3D confocal microscopy can provide important additional structural details compared with the 2D techniques as it allows the combination of true color information with 3D visualization. , In a recent confocal imaging study, we observed that diesel particulate matter (DPM), also known as diesel exhaust particulate (DEP), can have a sharp jagged surface appearance …”

“…However, 3D confocal microscopy can provide important additional structural details compared with the 2D techniques as it allows the combination of true color information with 3D visualization. 10,11 In a recent confocal imaging study, we observed that diesel particulate matter (DPM), also known as diesel exhaust particulate (DEP), can have a sharp jagged surface appearance. 11 Roadside particles consist of combustion-derived PM as well as PM from other sources such as those associated with road construction properties, tire particles, and brake dust.…”

“…10,11 In a recent confocal imaging study, we observed that diesel particulate matter (DPM), also known as diesel exhaust particulate (DEP), can have a sharp jagged surface appearance. 11 Roadside particles consist of combustion-derived PM as well as PM from other sources such as those associated with road construction properties, tire particles, and brake dust. 12 A recent study using SEM of particles deposited on leaves suggested that roadside PM can have a more spherical appearance compared with particles from other sources, 13 although that study did identify a range in particle shape and size.…”

Common methods in mitochondrial research (Review)

“…In most cases, microscopy can be used to observe and analyze two-dimensional mitochondrial morphologies and quantities. However, although this method is suitable for analyzing adherent cells with flat morphology, it is not suitable for thicker cells (77)(78)(79)(80)(81)(82)(83). Three-dimensional confocal microscopy can be used to observe mitochondrial morphology by observing specifically labeled mitochondrial proteins at the 3d level (84)(85)(86)(87).…”