2'-DEOXYPSEUDOISOCYTIDINE

2'-Deoxypseudoisocytidine is a modified base which can be used as a allele-specific blocker probe to discriminate sequence variation between different alleles and quantitate rare (e.g., mutant) allelic variants, such as SNPs, or nucleotide (NT) insertions or deletions, in samples comprising abundant allelic variants with high specificity and selectivity. 2'-Deoxypseudoisocytidine (2′d‐PIC) and its analogues are also used as novel base-pairing agents in oligonucleotides to investigate DNA and RNA structures and functions.