(1) ALWAYS wear gloves in the lab - don’t touch shit without gloves - when you don’t wear gloves you put RNases and keratins all over everything you touch. ALWAYS wear gloves - if you are not in this habit - get in this habit now. If I see you working in the lab without gloves, you are going to have a problem with me. The gloves dont just protect you from the chemicals, they protect your experiment from you.
(2) Always clean the surfaces around where you are working before you start to work - I do this diligently with distilled water and then 70% EtOH. Use windex if it is very dirty, followed by water and 70% EtOH - if you need a demonstration see me. The reason for this, (a) if you need to recover a lost extremely valuable sample from spilling, you just might be able to do it [trust me, this could happen to you] and (b) so that your actual bench space is not a source or introducing dirt, keratins etc into your experiments. If you need extra sterility, light a bunsen burner too.
(3) related to the above, when you take the lid off a bottle or a reagent container, please it “right side up” on the counter - that is, the threads should be facing down! If the bench is clean, then it cannot introduce contamination into the lid, and anyway, the lip of the lid keeps it slightly elevated from contact with the surface. If you put the lid ‘upside down’ then dirt and dust can fall into it - especially if you un-carefully reach over it. So, when working in the chemical room weighting things out - be sure to clean the counters and surfaces FIRST and to put the lids face down - read on.
(4) NEVER return and reagent BACK into a container - if you take too much reagent and you must save it (because it is precious and you really overdid it), then transfer it to fresh blue-top / falcon tube - put your intials, the date, and the chemical name + supplier + product number on there; return it to the chemical cabinet for YOUR later use. If you ever thing you contaminated something - throw it out. We lose more money on wasted time than on such things.
(5) ALWAYS pour regents out into a weigh boat - AVOID reaching into the container with e.g. spatulas etc (I have mostly avoid doing that my whole career - it’s completely possible). Sometimes you have to reach into the container with a spoon/spatula etc - that tool should have been thoroughly pre-cleaned before use with 70% EtOH. The container should be angled or tipped at its side and you avoid reaching in far, only at the neck of the bottle. IF this is not obvious to you - come see me - I will train you. NEVER reach into bottles with even your gloved hand holding a utensil, never be looking down into the bottle etc. Keep bottled caps when not using them - even if the cap is just resting on top (one thread tightened or you may knock it off)
(6) WHEVER you take a bottle out, always give it a quick swipe on the outside with 70% EtOH, especially around the neck of the bottle that you might be tipping over weigh boats etc. This is where dust accumulates, and then you end up dumping dust into your reagent etc