Aseptic Technique Lab

I made some changes to the Aseptic Technique Lab from the Flinn Lab Book (#4, I think). I took some of the pressure off of the kids by letting them practice more than one time into the nutrient broth tubes. I also noticed that the excellent diagram provided showed transferring from one tube into another, but the directions in the lab had students transferring from a petri dish into a broth tube. So I rewrote the lab slightly to just allow the kids to transfer from tube to tube. I will not have a control to check their aseptic technique, but I decided comfort level was more important to me right now. They will still be able to see if they contaminated one sample with their lab partner's sample because the E. coli samples should be turbid, while the B. megaterium should have a sediment. The kids really seemed to enjoy this lab. After they finished with their transfers, I let them use the microscopes again to practice their technique on some prepared slides. The slides with all three types of bacteria on them that I bought from Carolina Biological were terrific! The kids are really getting good at using the oil immersion objective. I was very pleased!