This happens about 2-3% of the time in people with celiac disease and can lead to false-negative test results. Common tests for celiac disease include: 1  Anti-tissue transglutaminase antibody (anti-tTG), IgA: detects antibodies to tissue transglutaminase, an enzyme that causes the crosslinking of certain proteins. 2  Anti-tTG, IgA is the most sensitive and specific blood test for celiac disease.
A contour line is a line drawn on a topographic map to indicate ground elevation or depression. A contour interval is the vertical distance or difference in elevation between contour lines. Index contours are bold or thicker lines that appear at every fifth contour line.
contour map. 1. a topographic map on which the shape of the land surface is shown by contour lines, the relative spacing of the lines indicating the relative slope of the surface. A contour map in colours such as Bartholomew's half inch is a great help in this matter.