Microbiology & sterility
Membrane filtration unit
A manifold with filter funnels connected to a vacuum source (or a peristaltic pump for closed canisters) that passes liquid samples through a 0.45 µm membrane so that microorganisms are retained and can be grown and counted.
- Pharmaceutical
- Biotech
- Water testing
- Food & beverage
- Medical devices
TROUBLESHOOTING
Common problems, causes and fixes
Filtration very slow or stops
Likely causes
- • Sample with particles or high viscosity
- • Weak vacuum or leak
What to do
- • Pre-dilute or use several membranes
- • Check seals and pump
Growth on negative controls
Likely causes
- • Non-sterile funnels or rinse fluid
- • Poor aseptic technique
- • Contaminated environment
What to do
- • Check sterilisation records
- • Retrain analyst and review EM data
- • Repeat with fresh materials
Low recovery in method suitability
Likely causes
- • Residual antimicrobial on the membrane
- • Wrong membrane type
What to do
- • Increase rinse volume or add neutraliser
- • Try another membrane material
Liquid in vacuum line
Likely causes
- • Trap full
- • Hydrophobic filter missing or wet
What to do
- • Empty trap and replace filter
- • Service the pump
In LimsPulse · Calibration Management
Keep every Filtration unit in control: usage logs, calibration and maintenance schedules, and automatic blocking of overdue instruments.