S1 Clickable UTP Analog for the Posttranscriptional Chemical Labeling and Imaging of RNA Anupam A. Sawant, Progya P. Mukherjee, Rahul K. Jangid, Sanjeev Galande* and Seergazhi G. Srivatsan* Electronic Supplementary Information Contents Page 1. Materials S2 2. Instrumentation S2 3. Synthesis S3 Scheme S1. Synthesis of azide substrates 5 and 9 for CuAAC reactions S3 Fig. S1 Phosphorimage of transcription products obtained from reactions with alkyne- modified UTP 3 S5 Fig. S2 PAGE of in vitro transcription reaction performed in presence of template T2 S6 Fig. S3 MALDI-TOF mass spectrum of alkyne-modified oligoribonucleotide transcripts 4 S7 Table S1 Yield and mass data of alkyne-modified RNA transcript 4 and 10 S7 4. Enzymatic digestion of RNA ON 4 S7 Fig. S4 HPLC chromatogram of enzymatic digestion of RNA ON 4 S8 Fig S5 UV-thermal melting of control unmodified duplex and alkyne-modified duplex S9 5. In vitro transcription with plasmid DNA template in the presence of 3 S9 Fig. S6 HPLC chromatogram of ribonucleoside products obtained from enzymatic digestion reactions of longer modified RNA transcripts containing 2 S10 6. Reverse transcription of alkyne-modified RNA transcripts containing 2 S10 Fig. S7 PCR amplified template sequence from pEGFPC1 vector used in transcription reactions S12 Fig. S8 Representative sequence alignment (BLAST) of PCR amplified DNA products S12 Table S2. Yield and mass data of posttranscriptionally functionalized RNA ONs 4 and 10 S13 Fig. S9 Posttranscriptional chemical modification of EU-modified RNA ON 10 by CuAAC reaction S14 Fig. S10 Posttranscriptional chemical modification of 59mer ODU-RNA by CuAAC reaction using Alexa594-azide 6 S15 Fig. S11 Incorporation of ODU 2 into cellar RNA transcripts as detected by CuAAC reactions using Alexa594-azide 6. S15 Fig. S12 Quantification plots showing percentage of labeled nuclei by click reaction S16 Electronic Supplementary Material (ESI) for Organic & Biomolecular Chemistry. This journal is © The Royal Society of Chemistry 2016