High quality total RNA isolation is difficult due to exogenous and endogenous RNase activity of Klebsiella pneumoniae. Guanidium isothiocynate (GuSCN) is commonly used in RNA purification protocol. Guanidium isothiocynate based method is effective when working with tissues that have high level endogenous RNase. During isolation procedure exogenous RNase degrades the total RNA, therefore, the procedure which can also inhibit exogenous RNase activity is required. Sarkosyl based method is effective for both exogenous and endogenous RNase. Three commercially available kits namely Trizol (GuSCN based), mirVANA RNA isolation kit (GuSCN based) and Ribopure Bacteria Kit (Sarkosyl based) was used for isolation of total RNA. Out of these methods, Ribopure bacteria kit gave high quality of total RNA from thermally stressed (15⁰C and 45⁰C) grown bacterial culture.