Amanda,
I perform monthly system cleaning for each of the three 494 sequencers that we
currently operate. I will give you the short version of the cleaning and
performance check that I perform (instructions for these cleaning procedures can
be found in the operators manual).
System Cleaning:
(1) Remove all filters from the cartridges and reassemble the cartridges with
clean seals, and leak test.
(2) With Methanol in position S2, perform the Cartridge line clean-up procedure
(Do Not perform this with samples in line).
(3) Place Methanol in the X1 position and complete the Clean transfer-line
procedure.
(4) Back-flush all bottle positions (Delivery line backflush procedure).
(5) Remove all reagents and cap them.
(6) Place clean empty bottles onto each position except X3 which will have MeOH
in place.
(7) Initiate System Clean-Out X3 procedure. This procedure delivers methanol to
each bottle position, so it is imperative that all reagents be removed.
(8) Complete Argon Flush procedure.
(9) re-install reagents using bottle change procedure. Wipe all residual
methanol from each line prior to installing the new bottle. I usually remove
the empty bottles prior to starting the bottle change this way the line is not
sitting in the small amount of methanol that has been delivered to each bottle
during the clean out.
If you have evidence of a contaminated cartridge you may want to perform a
preliminary cleaning prior to completing cartridge line clean-up procedure
above.
As stated in the operators manual, these procedures should be performed whenever
you see evidence of a possible contamination problem etc., as well as part of a
routine system cleaning.
Cartridge Cleaning Procedure:
All reaction cartridges are removed and cleaned according to the following
procedure:
(1) Sonicate cartridges for 10 minutes in HPLC grade Water.
(2) Sonicate cartridges for 20 minutes in 50% Nitric Acid.
(3) Sonicate cartidges for 10 minutes in HPLC grade Water.
(4) repeat water wash 2 additional times.
(5)Sonicate 10 minutes in 100 % Methanol.
The cartridges are place into small glass beakers or tissue dissection
containers for the cleaning, and a sonicator large enough to contain all 4
cartridges at a time is used. To state the obvious, be certain that the
sonicator is clean before starting (some people enjoy letting slime, mold,
bacteria etc. grow in their sonicator baths, we purchased one specifically for
cleaning purposes that never has standing water in it).
Reassemble dried cartridges with new seals and clean filters (with biobrene).
Complete filter preconditioning runs for each position.
I currently run 2 Beta-Lactoglobulin runs following this monthly cleaning
schedule alternating positions (A and C) and (B and D).
We also replace the conversion flask quarterly or if the pick-up line is
visually "corroded or discolored" than the conversion flask will be changed
sooner. We continually monitor and modify pre-conversion and post-conversion
dry times as well as sample concentration times to ensure efficient conversion
chemistry and good injections.
If I can be of any further assistance please let me know.
Raymond Boynton
Structural Biochemistry
N-Terminal Sequencing Core Facility
Biogen, Inc.
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