Abstract: After discussing why we are interested in tracing dense gas, I will present some recent observations of dense gas tracers in local molecular clouds. Then we will move on to observations of subsolar metallicity galaxies in the Local Group, where chemical differences change the way we should use standard lines as gas tracers. To probe the behavior of dense gas tracers in subsolar metallicity but low radiation field conditions, some very recent observations of outer galaxy Milky Way clouds with the Delingha telescope will be presented along with a preliminary discussion. Some conclusions from these datasets, along with their caveats, will be drawn.