Even if DNA is shared by all living things, there are some sequences that are specific to only one species. To ensure that the DNA extracted does really come from a snow leopard, you just have to detect a single sequence that is known to be found only in snow panther’s genome. To reach that goal, a probe is used to recognize specifically panther’s DNA. Other species DNA will not be recognized by that probe. Thus, when the results are analyzed, if a signal is witnessed, that will mean that the sample contains snow leopard DNA.