Coupling: Standard coupling time. Use 0.02 M Iodine for Oxidation.
Deprotection: Deprotect with1.0M DBU in anhydrous acetonitrile at Room Temperature for 2hrs to remove the cyanoethyl protection. Complete the deprotection with 50mM NaSH in concentrated NH4OH at Room Temperature for 24hrs.
Storage: Refrigerated storage, maximum of 2-8°C, dry
QUESTION: Can 4-thiodU be used for crosslinking and how is it prepared?
RESPONSE:4-thioU is efficiently activated for crosslinking by exposure to long-wavelength UV light for up to 10 minutes. Crosslinks are formed with RNA and proteins.
Oligonucleotides containing 4-thiodU (10-1051) and 4-thioT (10-1033) can be produced from the triazole modified phosphoramidites using the convertible nucleoside strategy (1,2). However, we now offer the nuclesides 4-thio-dT (10-1034), 4-thio-dU (10-1052), 2-thio-dT (10-1036), and 4-thio-U (10-3052) for direct incorporation into oligonucleotides and the convertible monomers have been discontinued. A further enhancement of this strategy used 4-thioxU as an intermediated in the preparation of thiocarbonyl crosslinkers (3).
REFERENCE(S): (1) Y.Z. Xu, Q. Zheng, and P.F. Swann, J. Org. Chem., 1992, 57, 3841. (2) The Glen Report, 1993, 6.1, 1, and references cited therein. (3) R.S. Coleman and J.M. Siedlecki, Journal of the American Chemical Society, 1992, 114, 9229-9230.
The table below shows pack size data and, for solutions, dilutions and approximate couplings based on normal priming procedures. Please link for more detailed usage information with the various synthesizers.