A presumptive field test designed to identify the semi-synthetic opiates of Heroin (white, brown and black tar). A distinct Green color will develop after the breakage and agitation of the 2nd ampoule. Due to brown and black tar Heroin having a dark resin, place very small amounts of substance in the pouch. If the Green color is not easily seen, turn the tube upside down, allow the dark liquid to drain into the new bottom of the tube and observe the Green color adhering to the glass shards at the new top of the tube. Like all our NARK narcotic field tests, the Meckes Modified Reagent is meant for presumptive field drug testing. 10 tests/box.