Deprotection: Levulinyl Deprotection: The levulinyl protecting group can be selectively removed without cleavage of the oligonucleotide from the CPG by treatment with 0.5M Hydrazine hydrate in 1:1 pyridine/acetic acid. [Note hydrazine hydrate is a violent poison that is both volatile and readily absorbed through skin] Fit the column with syringes and push the solution back and forth across the column. Let sit for 15 minutes at room temperature. Rinse the column with 1.5 mL of 1:1 pyridine/acetic acid (3x) and then 1.5 mL of ACN (3x). Dry CPG under a stream of argon and proceed with the synthesis of the branching sequence. If a non-branching control is desired, simply deprotect in ammonium hydroxide as required by the nucleobases.
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.