Bio-Rad ReadyPrep™ 2-D Cleanup Kit - Manual (Page 11)

At the end of the process, some pellet fragments may
remain undissolved. When using a urea/thiourea-based 2-D
rehydration/sample buffer, all the protein is extracted from
the pellet if the above protocol is followed.
14. Centrifuge the tube at maximum speed for 2–5 min at
room temperature to clarify the protein sample. The
supernatant can be used directly for IEF in IPG strips
or in IEF gels. Store any unused or remaining protein
sample in a clean tube at -80°C for later analysis.
4.2 Processing Dilute Samples or Samples Greater
Than 100 µl
The above protocol (Section 4.1) can be scaled to almost
any volume of original sample. For best results with larger
sample volumes, follow the additional recommendations
listed below for each step.
Maintain the sample tubes in an ice bucket during each
step of the procedure unless otherwise specified.
Always position the tubes in the centrifuge in the same
orientation so that the protein pellet remains on the same
side of the tube after each spin. This will minimize loss of
protein pellets during centrifugation and washing steps.
Use only polypropylene, polyallomer, or glass tubes for
processing large volumes as the wash reagent 2 interacts
with many plastics. Screwcap tubes are preferred to
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