SIMA phosphoramidite, 6-isomer is a xanthene dye with spectral characteristics similar to those of HEX but with a higher quantum yield. SIMA has higher stability during deprotection under alkaline conditions, so deprotection can be run with aqueous ammonium hydroxide at higher temperatures or with AMA (1:1 mixture, concentrated aqueous ammonium hydroxide/40% aqueous methylamine) at room temperature for 2 h or 65°C for 10 min. When used for deprotection with aqueous ammonium hydroxide at 55°C overnight, oligonucleotide-bound SIMA does not degrade, while with HEX the fluorophore degrades by at least 10%.
SIMA phosphoramidite is used in oligonucleotide synthesis to produce fluorescently labeled primers and hybridization probes for quantitative PCR.
AxisPharm offers 4000+ PEG Linkers with high purity. Different kinds of PEG Reagents may be available by custom synthesis.