Bacterial Contamination with Rapid Turbidity (Cell Culture (Contamination))

Question

Accepted Answer

Rapid-onset turbidity and color change of culture medium (when phenol red is present). Medium becomes cloudy and pH indicator changes color quickly. Common causes: 1) Poor aseptic technique during manipulations and pipetting 2) Nonsterile surfaces and equipment in biosafety cabinet 3) Spillage on bottle necks and work surfaces 4) Touching pipette tips or bottle necks during handling 5) Aerosols from operator talking, coughing, or sneezing 6) Inadequate sterilization of reagents and media 7) Contaminated commercial supplies from unreliable sources Solutions: 1) Clear work area and swab surfaces regularly with 70% alcohol 2) Dispense liquids by pipette or autodispenser, never pour 3) Hold pipettes above graduations, handle by overwrap sleeve 4) Use vacuum to draw off waste, avoid splash-back from beakers 5) Never pass hands over open vessels, face away when talking 6) Wear lint-free lab coat reserved for culture room, tie back hair 7) Filter or autoclave all solutions before use, monitor autoclave performance 8) Obtain media and sera only from reputable certified suppliers 9) Promptly remove contaminated cultures to protect neighboring cultures