Wash
To completely clean the resin
after a deprotection or coupling reaction, the
beads are typically washed four to six times with
solvent. The typical protocol for washing is:
1. Fill the reaction vessel
with approximately 10mL of solvent (DMF, NMP)
per 0.5g of resin.
2. Bubble the mixture for several
seconds.
3. Immediately drain the reaction
vessel through the filter.
Repeat steps 1-3 a minimum of
four times.
Sign of Poor Washing
Amino Acid Addition - if the
peptide product contains an amino acid insertion
in the sequence, this could indicate poor washing.
This could be caused by piperidine remaining in
the reaction vessel during the coupling reaction
or activated amino acid during the deprotection
reaction.
If this problem occurs:
1. Increase the wash cycles
between each reaction.
2. Check the spray head in the
top of the reaction vessel to ensure washing of
the vessel walls
|