text: why is it important to hold open culture tubes in a horizontal position? help!!! i have lab questions that are not answered in any text that i have. i am taking microbiology for the health sciences. well, if you do that, it have to contain gelified culture media... ( that's logical )   if the culture tube has to remain open, you need to hold it in an horisontal position to prevent the bacteria contained in the air to fall in the tube...