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Showing posts from August 29, 2010

Brief update: Testing my PCR thermocycler

The first tests gave me temperature readings that were off by 30 degrees C from what I'd expect from the thermocycler program I was running. Next up are some auxiliary tests to make sure my setup isn't producing errors. I strongly suspect it is. However, that'll have to wait until the current day job project thing is done, which is keeping me away from Vienna and thus my lab for five days a week. Lesigh.

Genetic engineering bits and pieces: Codon bias

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Random thing I learned today: One of the many details one has to pay attention to when genetically modifying an organism revolves around a thing called codon bias. What led me to this bit of information is part of a writing assignment for the course "Laboratory Fundamentals of Biological Engineering", taught at MIT. Here's part of the documentation for this course. The question was this:
"Would you expect the phage to tolerate p8 modifications that encode all Leucines with the CTA codon instead of the CTG codon? Would you expect the phage to tolerate these same modifications to p3?"
When the authors ask whether the phage would "tolerate" this or that modification, I assume they mean to ask whether the phage would still be active and reasonably effective after the modification. Leucine is an amino acid. p8 signifies the protein VIII of bacteriophage (a virus that infects bacteria) M13. Proteins, of course, are chains of amino acids. A codon is a triplet …