3.4 Contamination diagnostics and troubleshooting

Here’s a professional, course-ready infographic-style content layout for Contamination Diagnostics and Troubleshooting in Aquilaria tissue culture, designed for COPI labs, SOP manuals, and training courses. You can later convert this directly into a visual poster or infographic.


Contamination Diagnostics & Troubleshooting in Agarwood Tissue Culture


1. Types of Contaminants

ContaminantVisual SignsGrowth PatternLikely Source
BacteriaCloudy or turbid media, slimy film, tiny coloniesRapid, spreads throughout mediaExplant surface, operator handling, water
FungiWhite, grey, black mycelium; sporesSlower than bacteria, aerial growthAirborne spores, poor asepsis
YeastsMilky or turbid patchesModerate growthExplant tissue or water
Endophytic microbesDelayed contamination (7–14 days), localizedSlow, often hidden in tissueInternal explant contamination, resistant to surface sterilization

2. Diagnostic Methods

  1. Visual Inspection
    • Daily check for turbidity, discoloration, mycelium growth, bubbles.
  2. Microscopic Examination
    • Differentiate bacteria from fungal spores.
  3. Media Response
    • pH changes or color shifts in indicator media.
  4. Sample Testing (Optional)
    • Swab tissue, plate on selective media for identification.

3. Troubleshooting Table

ProblemPossible CauseCorrective Action
Cloudy media, rapid spreadBacterial contaminationIsolate culture, discard contaminated media, review sterilization
Mycelium on explantFungal contaminationRemove affected tissue, transfer clean portions, improve sterilization
Slow contaminationEndophytesPre-treat mother plant, optimize sterilization agents, consider HgCl₂ under safety protocols
Browning / necrosisOver-sterilization or oxidative stressReduce sterilant exposure, rinse thoroughly, use antioxidants
Recurrent batch contaminationAirborne spores, operator errorCheck LAF airflow, clean surfaces, retrain personnel

4. Corrective Workflow (COPI SOP)

  1. Identify type – visual/microscopic confirmation
  2. Isolate affected culture – prevent spread
  3. Determine source – explant, media, environment, operator
  4. Decide action – discard or salvage tissue
  5. Document – date, batch, contaminant type, corrective steps
  6. Revise SOP / Retrain personnel – prevent recurrence

5. Preventive Measures

  • Strict adherence to aseptic technique
  • Regular LAF cabinet maintenance & HEPA filter replacement
  • Use fresh sterilants & sterile consumables
  • Monitor and quarantine new explants
  • Maintain a contamination log for continuous improvement

6. Key Principle for COPI Course

Early identification and systematic troubleshooting of contamination ensures high survival, preserves genetic fidelity, and supports reproducible, high-quality Aquilaria propagation.


If you want, I can convert this into a print-ready infographic / lab poster with flow diagrams, icons for contaminant types, and stepwise troubleshooting arrows to make it visually intuitive for technicians and trainees.

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