How to Reduce Background and Contamination

Dust = high Gly +Ser + Ala

  • Locate instrument in a low traffic area
  • Keep the room clean and tidy
  • Keep covers and panels on the instrument
  • Protect pipets and pipet tips
  • Keep tips in a dust-free, covered box
  • Don't touch pipet tips with your hands
  • Wear gloves as needed (powder free)
  • Clean/calibrate pipetters regularly


Instrument Location is Important

  • Low traffic area = less dust
  • Clean area = less dust
  • Lab air quality/circulation = more dust?
    Avoid heater/air conditioner vents
  • Peptide synthesis area = contamination.
    Keep separate from AAA if possible
  • Sunlight = enhanced bacterial growth.
    Use amber solvent bottles. Avoid direct sunlight


Old Reagents/Chemicals=Problems

  • Low traffic area = less dust
  • Use newest lots available from supplier
  • Date reagents as received in the lab
  • Change chemicals every 1-2 weeks
  • Use HPLC grade solvents and water
  • Monitor HPLC solvents for bugs/floaters
  • Avoid direct sunlight
  • Filter solvents before use
  • Keep solvent reservoirs covered


Metal Contamination=low Asx/Glx

  • Precolumn Derivatization Problem Only
  • Use volatile, salt and metal free solvents
  • Dissolve hydrolysates in 0.025% EDTA
  • Use clean, quality hydrolysis supports
  • high quality borosilcate glass tubes
    Example=Corning 9820 Culture tubes 6x50 mm
  • high quality porous glass frits
    Example=Applied Biosystems AAA slides


Sample Handling is Critical

  • Avoid unnecessary opening/closing of vials
  • Minimize "open time" for sample vials
  • Be Organized
  • Determine loading position first
  • Make necessary log book entries
  • Wear dust free gloves as needed
  • Think clean
  • Tubes/hydrolysis vessels
  • Pipet tips
  • Micro pipets


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