Some common indicators used in the Living Environment laboratory are:

1.)  Litmus paper -- turns red in acids/blue in bases

-----------------------------------------------------------------------------
 
 

2.)  Benedict's solution -- used to detect simple monosaccharide sugars like glucose -- it is a blue solution that will turn red-orange (brick red) when heated in the presence of glucose (note that the sucrose solution does not change color in the test at the left as it is a dissacharide (double) sugar)

 
 

3.)  Lugol's (iodine) (IKI) solution -- turns from brown to blue-black or black in the presence of STARCH -- note the positive test in the potato that contains starch

 

4.)  Bromothymol blue -- this is a test for the presence of either carbon dioxide or acids -- the solution will stay blue if no carbon dioxide is present (like on the far right) -- but will turn yellow in the presence of excess carbon dioxide gas when bubbled into this solution (like in the tube at the far left) -- this solution will also turn yellow in acids

The images of the Lugol's and Benedict's tests were due to the courtesy of Professor Michael Shaw of the University of Manitoba. The bromothymol blue test was courtesy of Rutgers University.