Using Kuala pear leaves and cortexes as materials, the total RNA was extracted using two methods and these two methodswere compared. The most suited methods for Kuala pear were screened; and biotin-labeled cDNA probe was synthesizedusing RT-PCR. The main factors that affected the sensitivity of hybridization were studied. Studies indicated that thehighest sensitivity was obtained under the following conditions: probe concentration 400 ng mL-1, formamide concentration45%, temperature 42°C, hybridization time 6 hours. The best hybridization results were obtained when the nitrocellulosemembrane purchased from Gelman was used. Better blocking of hybridization was obtained using Tween 20 comparedwith albumin in bovine. The detection of the total RNA using different tissues and different extraction methods wascompared. This study indicates that the total RNA of fresh leaf, old leaf, cortexes, and frozen leaf showed signs ofhybridization using the two extraction methods.
