|MadSci Network: Molecular Biology|
Hello Timothy! Wow, what an interesting experiment! Plasmid size, or rather the size of the insert, does affect transformation rate. From what I have read, the size of the insert is inversely proportional to the efficiency of ligation and transformation. The magic number is around 15kb for the insert. Any foreign DNA larger than that and the plasmid may "spontaneously lose the insert"(1). Just to put things in perspective, the protocols for nested deletions that I found gave recipes for inserts around 2kb. So, if you start off with a fragment the size of 15kb and create nested deletions down to several 100bp, you should see quite a change in transformation efficiency :) Best of luck and I hope to hear about your results! Evelyne My references: 1. Griffiths, et al., "Ch.14, Recombinant DNA Technology" from "Genetic Analysis 6th ed." 2. Zubay et al., "Ch. 27, DNA Manipulation and its Applications" from "Biochemistry, vol.3" 3. Slatko, B, Heinrich, P, Nixon, BT and Voytas, D. (Contributors in)"Ch. 7.2, Constructin Nested Deletions for Use in DNA Sequencing" from "Short Protocols in Molecular Biology"
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