RNA Extraction Method (Guanidinium Thiocyanate-Phenol Method) The extraction of RNA is an essential and basic step in any molecular biology experiment such as RT-PCR, cDNA library construction, sequencing, gene expression studies, microarray analysis, etc. There are different types of methods available like CsCl density gradient method, silica column based method but the guanidinium thiocyanate or guanidium isothiocyanate-phenol-chloroform method is the most important and is the common one. Now