How to inoculate bacteria? - (Nov/11/2009 )
HomeBrew on Nov 12 2009, 07:53 PM said:
jiajia1987 on Nov 12 2009, 02:27 AM said:
I often use a DNAzap to clean my pipette barrels. Plus, I do not put my pipette barrels into the opening of the flasks. I simply put the tip at the opening and by ejecting using the pipette ejector, it will be 'forced' into the media.
I understand that this must work for you or you wouldn't be doing it, but I'm still confused -- unless the outer surface of your pipette barrel is sterile, then the inside surface of your pipette tip could become contaminated where it contacts the barrel, and carry that contamination into your culture when you eject it into the media. How do you protect against this?
Just like Kami23, I always use sterile pipette tips and have no problems with it. My colleague has no problems with it too. I also clean the opening of the pipette barrels when I clean them. Sometimes, I just pick up a pipette tip by hand and drop it in. No problem it!