Contamination issues - (Mar/22/2005 )

# About sterile techniques; for example the package which is for the culture tubes. When i use one of these tubes, should i open the package outside the hood. Wipe the culture tube with EtOH before putting it on the hood or should i wipe the whole package with EtOH before putting it on the hood and open it to get the tube?

# About the laminar flow hood; when should i turn off the blowers which circulate the air? After the work or should it be on all the time? Can i have it on at the same time with the UV light?




Thanks.

---

You should spray the package and then bring it into the hood and open it there.

Turn on the blower 15 min before using it. After using it, turn off the blower and turn on the UV light.

---

Is that not more safety if i wipe the tube instead of the package since the tube is less than the package and if the package is already opened then the bacteria may come inside of it and if i only wipe outside of it then i can contaminate my cells if i open the package inside my hood? What do you think?


So i have to turn on the UV light all the time except when i work? I thought i should leave the blowers on 24/7 and turn on and off the UV light after work and before work for only some minutes.

Thanks.

---

hi
you better spray the package and open it into the hood. that is better than spray each tube. and once sprayed, the package can be kept in the hood.

activate hood 15' before using it will ensure fresh sterile air; but you're right.10' of uv light will sterilize the hood.

---

So in this case the tube does not need to be sprayed, since it is already in the hood? Or should i spray it in the hood?


I get different answers in this issue which makes me confused. So again, should i leave the UV light 24/7 when i don't work?

Should i turn the blowers off when i have the UV light on?

Should i have the blowers on when i work?

Should i turn the blowers off when i don't work?


Thanks for any inputs which clare my mind.

---

yep

usually i close the hood and turn off the blower when not working. Then nactivation of uv light during 10'

---

Dont keep the UV on while you are using it. As UV radiation is not so good for health. and also I feel, it may some times have negative effect on your experiments especially if you want to study proteins or so..what do you say?

You can keep your hood on 24/7 inorder to maintain sterile environment. But, Dont you thinks its too noisy?

Here is my procedure

1. Turn OFF UV
2. lift the SASH
3. Turn ON blower and light
4. Leave it for 15 min
5. Wipe the hood with 70% alcohol
6. Bring medium and PBS out from fidge
7. Wipe it with 70% alcohol
8.Place it in the hood
9. Spray it with 70% alcohol and leave for 2-3 min

10. After all experiments are done cut parafilm and place it around the cap of medium and PBS
11. keep it in fridge
12 wipe off the hood with alcohol
13. switch blower and light
14. close SASH
15. Switch on UV


--if your hood is also used by some other person, its better to turn on UV for few min and then spray and use it for ur experiments.

---