CEM liberty - Page 39

Liberty
™
Automated Microwave Peptide Synthesizer
600178 • Revision 5 • October 2009
37
C-Terminus: This corresponds to the type of resin used. Selecting 6.2. Acid
assumes the resin is preloaded (the rst amino acid is already attached)
and therefore skips that coupling. If the resin is not preloaded, Amide
should be selected.
6.3. Final Deprotection: If No Final Deprotection is selected, the N-terminal
Fmoc group will not be removed from the peptide prior to cleavage.
Default Cycles:6.4.
Resin: The resin loading cycle selected depends on the reaction 6.4.1.
vessel required for the synthesis.
Cleaving: To cleave the peptide on the system automatically, select 6.4.2.
the Cleavage cycle. The cleaved peptide will be transferred to the
Product position on the Liberty. Selecting Non-Cleavage will skip
the cleavage step and return the peptide on resin to the same Resin
position from which the resin was loaded.
Final Deprotection: By default, the N-terminal Fmoc group is 6.4.3.
removed and left as the free amine. To perform N-terminal
acetylation, select the Acetylation method from the Final
Deprotection pull-down.
Enter the substitution value in the Resin Substitution box. This value is provided 7.
by the supplier of the resin, and is usually expressed in mmol/g or meq/g
8. Assign cycles for each residue in the sequence that will not use the default cycle.
Click on the amino acid to highlight it.8.1.
NOTE
Acetylation requires capping solution to be prepared and loaded on the
Liberty in the Capping bottle.
NOTE
The 125 mL vessel must be used for syntheses above 0.25 mmol, and the
Large Vessel - Resin method should be selected.
The 10 mL vessel assembly must be used for syntheses below 0.1 mmol,
and the 10 mL Vessel - Resin method should be selected.
NOTE
The substitution value entered here will not affect the operation of the
Liberty. It is only needed for the Usage Calculator to calculate how much
resin is required for the synthesis.
NOTE
Each amino acid is assigned an optimized default coupling cycle. By default,
the Double Arg cycle is used for arginine, and the Single 50 C cycle is used
for cysteine and histidine. The Single coupling cycle is used for all other
amino acids. To restore all amino acids in a sequence to the default cycles,
click the Restore Defaults button.