Difference between revisions of "Normalfreezer expt"
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<br> | <br> | ||
=First Test= | =First Test= | ||
| − | We wanted to test the method of Cody et al 2008, J Microbial Methods. | + | We wanted to test the method of Cody et al 2008, J Microbial Methods. testing 10% skim milk for stocking bacterial strains vs. the normal 15% glycerol conditions. |
<br> | <br> | ||
| − | The bacterial strain DH5alpha was inoculated on 15oct and grown in LB o/n at 37<sup>o</sup> | + | The bacterial strain DH5alpha was inoculated on 15oct and grown in LB o/n at 37<sup>o</sup>C with shaking in LB media.<br> |
| + | To note: you should not autoclave milk powder!! | ||
| + | |||
| + | On 16October. | ||
| + | Made up 20% milk powder, but did not have sterile filters, so just used it for this test... <br> | ||
| + | Made good 30% glycerol (sterilized no problem, in autoclave - when the milk got carmelized). <br> | ||
| + | |||
| + | Made 2 big Nunc freezing tubes with each combination, 1/2 E coli culture and 1/2 milk or glycerol. <br> | ||
| + | Put all 4 vials into the freezer in a styrofoam chunk to let freeze gradually. <br> | ||
| + | |||
=Second Test= | =Second Test= | ||
| + | On 2 November, streaked out 2 plates with the frozen cultures.<br> | ||
| + | Both grew very well!<br> | ||
| + | |||
=Conclusions= | =Conclusions= | ||
Revision as of 15:03, 3 November 2017
The P1 lab is official at Hackuarium (as of 1nov17), and we really want to know if we can get away with using the normal -20 freezer to stock strains.
(If someone would like to help for translations to French or other languages, please do feel free!)
First Test
We wanted to test the method of Cody et al 2008, J Microbial Methods. testing 10% skim milk for stocking bacterial strains vs. the normal 15% glycerol conditions.
The bacterial strain DH5alpha was inoculated on 15oct and grown in LB o/n at 37oC with shaking in LB media.
To note: you should not autoclave milk powder!!
On 16October.
Made up 20% milk powder, but did not have sterile filters, so just used it for this test...
Made good 30% glycerol (sterilized no problem, in autoclave - when the milk got carmelized).
Made 2 big Nunc freezing tubes with each combination, 1/2 E coli culture and 1/2 milk or glycerol.
Put all 4 vials into the freezer in a styrofoam chunk to let freeze gradually.
Second Test
On 2 November, streaked out 2 plates with the frozen cultures.
Both grew very well!