collective precautions - for newbie in th lab (Oct/11/2006 )
hi
to all members of bioforum.now first time i am entered in lab for something serious .i am a beginner.
if every person shares a single precaution , from his experience.it would be great help for new workers .
(u all persons are masters and experiensed.i feel would it be a stupid question)
thanx to all . 
Let's try,
one advice I gave today :
IP :don't throw away the supernatant when you wash your beads. you could have forgotten something , used the wrong antibody... you could also re-use it to IP something else, for some preliminary experiments.
as a general advice, don't throw anything until you get your result, especially if you have several steps where you have to keep once the supernatant, once the pellet. you can get confused very quickly, especially when you do it for the second time, while you believe you know the protocol and eventually realise you made a big mistake.
I am bad in calculations so i advice my students to take time getting calculations right and not worry abt the calculations if any of the experiment doesnt work.
Label everthing (bottles, cups, samples), write down everthing you did, what you changed etc. Make a plan of your work before you start.
When adding something to a lot of tubes, line them up in a rack and move each tube to a different location after addition. Do this the same way everytime. Then if you get interrupted halfway through you won't forget which tube you added it to.
Similarly, when making a solution with several components like a PCR master mix, place each ingredient in a rack or ice bucket. After addition move each ingredient to a different location. Also, make a list of each component and check it off after adding. This will save you a lot of headache when you wonder if you forgot to add something.
If the experiment fails, don't mindlessly attempt to repeat it. Something is wrong and repeating exactly what you did before, would probably result in the exact same failed experiment.
If a PCR reaction fails and the problem cannot be resolved by changing annealing temperature, the cause it is often the template.
label the lids as well as the side of the tube, (flask... whatever).
also, when doing a PCR, try to list the ingredients by how much you use, rather than all over the place. nothing is more annoying that using 4uL of primer A, 1 uL of dNTP, 5uL of buffer, 4uL of primer B ... changing the amount of the pipette up and down and back to an amount you already used is tedious.
always check before you do an experiment that there is enough reagent to complete it. you'd be suprised how often an enzyme that "only you use" magically dissapears.
keep LB in the fridge rather than on the bench. same goes for SOB and SOC.
When making up a master mix, always add an extra 1 or 2 reactions in it to account for pipetting errors.
Label your pipettes and defend them with your life.
V
label everything and keep your stuff in meticulous order. write down every detail, and make sure you are writing down what you actually do, rather than what you meant to do. i've looked back in my notes and found that i added the wrong solution. had i not written EVERYTHING down, i would have never figured out what i did wrong. the more organized you are, the less chance you have for random error.
also, i've found that if i am doing something i need to focus completely on, if i wear headphones nobody talks to me. even if i am not listening to music, people are less likely to bug you with trivial questions or anecdotes if you have headphones in. 
Understand the lab heirachy and politics very early on!
wear gloves all the time! work in hood when applicable and necessary. read about the chemical BEFORE you use it.
don't wear open shoes in the lab, do wear a labcoat!
read read read read read.........