Methods of measurement and detection employing photosensitive compositions and products

A method for measuring the presence of bioactive materials known to absorb ultraviolet light energy comprising:

• A. disposing a quantity of a medium suspected of containing at least one of said bioactive materials in a container transmissive to ultraviolet light energy;
• B. locating said container in the path of a beam of ultraviolet light energy emitted from a source therefor;
• C. locating an indicator sensitive to said light energy beam in operative position adjacent said container and in the path of said light energy beam to receive any of the light energy of said beam that may pass therethrough, said indicator comprising a water and solvent-insoluble substrate on which is disposed a quantity of a photosensitive composition consisting essentially of a complex of a hydrophobic leuco dye and animal-derived serum albumin, said leuco dye and said serum albumin are bound to each other in said complex by hydrophobic bonds;
• D. activating said light energy source to direct said beam against said container;
• and
• E. determining the presence of said bioactive materials by inspecting said indicator after said beam has been directed against said container to measure the presence and amount of any of said light energy absorbed by said indicator, wherein the absence of a color reaction on said indicator reveals the presence of said bioactive materials.