[Comparison of three different methods for isolating RNA from Oncomelania hupensis]

To compare the effects of three kinds of Oncomelania hupensis RNA extraction methods, namely a modified SDS method, TRIzol reagent method, and CTAB method, so as to obtain an economical and efficient method for RNA extraction from O. hupensis.

The modified SDS method, TRIzol reagent method and CTAB method were applied to extract the RNA from O. hupensis. A nucleic acid protein analyzer was used to measure the concentration and purity of RNA. The yields were calculated by the concentration of the products. The purity was indicated by A₂₆₀/A₂₈₀ and A₂₆₀/A₂₃₀. The quality of RNA was inspected by 1% agarose gel electrophoresis. The β-acting gene was selected as the target gene for RT-PCR analysis.

The RNA yields obtained by using the three kinds of extraction methods were significantly different (F = 16 895.85, P < 0.01) according to the analysis of variance. The LSD test showed that the yields obtained by using the modified SDS method were the highest, and those obtained by the CTAB method were the lowest. The purity of RNA extracted by the CTAB method was superior to that by the other two methods, and the A₂₆₀/A₂₈₀ and A₂₆₀/A₂₃₀ ratios of the CTAB method were in the range from 1.8-2.0 and 2.0-2.2. The A₂₆₀/A₂₃₀ ratios of the other two methods were both lower than 2.0. The RNA extracted by the modified SDS method had the better integrity. The electrophoresis results showed that the 28S rRNA band, 18S rRNA band and 5S rRNA band were clear, and there was no obvious smear between each band. The RNA obtained by the TRIzol reagent method had no 28S rRNA band, and that obtained by the CTAB method had no 28S rRNA and 5S rRNA bands. The β-acting gene of the RNA extracted by all the three methods could be amplified by RT-PCR. The costs and time-consuming of the modified SDS method were less than those of the other two methods.

The modified SDS method is an economic and efficient method, and it is suitable for extracting the RNA of O. hupensis, especially for large sample preparation.