The cDNA library was constructed from mRNA isolated from wounded cotyledons of 11 day old seedlings that were treated with 2 ugs/ml of a crude glucan elicitor preparation isolated from the mycelial walls of Phytohthora sojae. The library was prepared using the Stratagene pBluescript II SK (+) library construction kit. Complementary DNA was synthesized from mRNA using a primer consisting of a poly (dT) sequence with an Xho I restriction site. Eco RI adaptors were ligated to the blunt-ended cDNA fragments followed by Xho I digestion. The cDNA insert is protected from Xho I digestion via methylation during first strand cDNA synthesis. The cDNA fragments were directionally cloned into the Eco RI-Xho I restriction site of the pBluescript vector. The ligated cDNA fragments were transformed into E. coli ElectroMax DH10B host cells.
Transformation efficiency: 1.6 x 10 10 colonies/ug of vector DNA
Titer of cDNA clones: 5 x 106 CFU/ml
Percent white colonies: 88%
Average insert size: 1.0 Kb
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