The kit can be used with cultured cells. Biological samples are first lysed and homogenized in a strong denaturant containing buffer, which immediately inactivates RNases to ensure isolation of intact RNA. After homogenization, ethanol is added to the lysate, creating conditions that promote selective binding of RNA to the silica-based membrane. The sample is then applied to the Spin Column, where the total RNA binds to the membrane, then the membrane is treated with gDNA Remover to eliminate the DNA. Contaminants are efficiently washed away by subsequent step of washing. The high-quality total RNA is then eluted in Elution Buffer. The purified total RNA is suitable for use in a variety of downstream applications, including: RT-PCR, RT-qPCR, and so on.