Do the amino acids have to be pre-activated for CelluSpots™ synthesis?No, the
MultiPep RS can
activate amino acid derivatives specifically for each cycle. There is a
dedicated activation vial for each amino acid. Of course, pre-activated
amino acids can also be used.
Will the individual discs be deprotected in the instrument?
Yes, the MultiPep RS spots
piperidine solution on the discs to take the Fmoc protection group
off in each cycle. The synthesis plates with individual discs can stay in the instrument for the
entire synthesis.
How are the discs washed and dried for the next coupling?
The discs is clamped tightly in a 384-well synthesis plate. The bottom has tiny holes to remove solvent by vacuum
aspiration. Solvent is delivered on the upper face of the discs and
pulled through by vacuum. A longer extraction time is being applied to
remove ethanol from the final wash and to dry the discs.
Is the rinsing action sufficient if a full set of peptides is built on the discs?
Yes,
the flow-through mode of washing is very effective and makes economic
use of the solvents.
Can we still use Bromophenol blue (BPB) to monitor the reactions?
The MultiPep RS can
be programmed to deliver BPB at the appropriate steps in the cycle to
stain amino groups on the peptides assembled. The stain is removed with
the next coupling reaction as it is done in manual procedure, too.
Is there any possibility of piperidine carryover?
As
piperidine is used in a very large excess it must be removed
thoroughly. The washing procedure is designed to remove all traces of
the reagent before the next coupling will be started.
What is the synthesis time for two sets of 384 each 10-mer peptides?
With
a recommended double coupling of 2x30 min, 2x5 min deprotection and all
washing and drying steps, the total cycle time is about 2.5-3 hours and
the two sets of 10mers would be assembled in a little more than a day.
Can the synthesis be interrupted and started again?
The
MultiPep RS can
be stopped and re-started at any time. Several convenient options allow
manual procedures (e. g. Bromophenol blue staining or introduction of
very unusual derivatives) and safe re-starting in any cycle.