Table 1.

Major characteristics of validation methods listed in this chapter.

Validation Method	Biochemical/Biological Principle	Main Features
Sanger sequencing	DNA synthesis reaction using a mixture containing the four dNTPs and chain terminating labelled ddNTPs in established concentrations.	Targeted approach; direct; need of customized optimization; time-consuming; applicable to multiple editing types.
SNaPshot	Extension of primers complementary to selected cDNAs by one base (in correspondence of the modified base) in a reaction solution containing the four dNTPs and labelled ddNTPs.	Targeted approach; direct; no need of customized optimization; time-effective; applicable to multiple editing types.
I-specific cleavage (chemical-enzymatic approach)	Glyoxalation of guanines and inosines and subsequent cleavage of inosine adducts by Ribonuclease T1. Guanosine adducts are protected by borate.	Targeted approach; direct; no need of customized optimization; time-effective; specific for A-to-I.
I-specific cleavage (enzymatic approach)	Cleavage of A-to-I edited RNAs by EndoV, the ribonuclease specific to inosine-containing RNAs.	Targeted approach; direct; no need of customized optimization; time-effective; specific for A-to-I.
ADAR KD	Downregulation of ADAR expression by RNA interference (RNAi) mechanism.	Wide-range approach; indirect; need of customized optimization; time-consuming; specific for A-to-I.
ADAR KO	Total suppression of ADAR expression by gene loss or inactivation.	Wide-range approach; indirect; need of customized optimization; time-consuming; specific for A-to-I.