Comparison of different methods of RNA preparation from peripheral blood for nucleic acid amplification assay

Nucleic acid amplification assays (NAAs), such as polymerase chain reaction or loop-mediated isothermal amplification (LAMP), are used for disease diagnosis. Current nucleic acid isolation kits require several hours for completion of protocol including the complicated handling steps.

In this study, a simple and cost-effective nucleic acid preparation method was developed, and its performance was compared with those of commercial kits.

RNA was prepared using our method and three commercial RNA isolation kits. The RNA quantity and quality were evaluated using the NanoDrop spectrophotometer and Agilent 2100 bioanalyser. Reverse transcription LAMP (RT-LAMP) reactions were performed to determine the usability of the RNA preparation methods.

The concentrations of RNA extracted from blood samples by four different methods were sufficient for use in NAAs. The RNA integrity number was> 7.0 when RNA was isolated using other RNA isolation kits but lower when prepared using our method. The RT-LAMP reaction was successfully performed when RNA was prepared using any of the methods.

These results demonstrate that despite the lower purity and integrity of RNA, our RNA preparation protocol is simple and rapid and shows reasonable performance in RT-LAMP.