Comet Assay welding fumes

At least 50 total cell comets from 2 independent experiments were measured for the percentage of DNA in comet tails per condition. This was calculated by determining the background-corrected fluorescence from:  the nuclear region of interest in a cell (nuclear ROI) and the total cell fluorescence for a defined region of interest (total cell ROI). ImageJ software was used to measure the “integrated density” (the sum of the values of the pixels in the selection) for regions of interest, and Microsoft Excel was used to calculate the corrected fluorescence values and ratios of nuclear ROI to total cell ROI. This was converted to a percentage of DNA in the “tail” (100 – [(nuclear ROI/total cell ROI) X 100]), with elevated percentages indicating DNA damage.

Area: Area of selection in square pixels

Integrated Density - Calculates and displays two values: "IntDen" (the product of Area and Mean Gray Value) and "RawIntDen" (the sum of the values of the pixels in the image or selection).

CTCF: corrected total cell fluorescence. (intDen - (area x mean fluor bkgd)