Mutations in Bacterial Cultures
Don't Worry - Be Careful!
Treat all micro-organisms with respect - and DO NOT touch
them!
Remember, mutations arise because the sequences of bases
change in the DNA. These changes can change the organism.
Could it change the bacteria to something pathogenic? Possibly.
Let's see...
Spontaneous Mutations
Occur because of environmental factors (radiation from cosmic
rays, certain chemicals) and errors in base pairing during
replication. The rate:
approximately 1 in every 100,000 to 1,000,000.
Seems low? Figure this:
- Let's say, the mutation rate in a given bacteria is 1
in every 100,000.
- Grow the culture to a concentration of 1,000,000,000
per milliliter.
- Grow 100 milliliters of the culture.
- How many possible mutations are there?
- Answer: about 1,000,000 mutations
Conclusion: Be careful with all micro-organisms!
Disposing of Cultures:
ON PLATES: Put the plate in the autoclave bags in the marked
"biohazard" containers. Make sure these bags
are autoclaved regularly!
LIQUID: Put a drop or two of bleach per 100 ml in the culture
before drain disposing. Flush the drain well with water.
Check out this site: http://falcon.cc.ukans.edu/~jbrown/ecoli.html
QUESTIONS? Call the Biosafety Officer at X2507 the the
safety office at X7233.
Revised: 7/2001