[Description]
SIMA (dichloro-diphenyl-fluorescein) 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.
Coupling: 3 min.
Deprotection: Standard conditions with 25% ammonium hydroxide; deprotection time depends on the composition of nucleic acids and their protective groups. AMA (1:1 mixture of concentrated aqueous ammonium hydroxide / 40% aqueous methylamine) can be used for 2 hours at room temperature or 10 min at 65°C. |