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UV Light Efficiency Test


Learn how to test the Efficiency of UV Light of Laminar Air Flow (LAF) unit using the petridishes containg Bacillus subtilis.

1.0  Methodology

1.1  Prepare SCDA medium as per SOP for preparation of culture media.
1.2  Aseptically pour approximately 15-20 ml of sterile molten cooled (40 - 45°C) SCDA agar into sterile 90 mm petri plates under LAF.
1.3  Allow the media to solidify the plates under LAF, after solidification label all the plates with name of media, preparation batch No. and date of preparation.
1.4  Invert and incubate the plates at 30 to 35°C for 24 hrs in BOD Incubator. After incubation physically inspect the plates for any contamination (Macroscopic growth of evidence), if there is contamination discard the plates as per SOP for Destruction of Microbial waste by Autoclaving,.
1.5  After pre-incubation, transfer 1 ml of not less than 105 cfu per ml culture of Bacillus subtilis to two SCDA Petri plates & spread the colony using sterile spreader. (Prepare 106 Bacillus subtilis cfu per ml suspension)
1.6  Now wrap one Petri plate containing Bacillus subtilis  in Aluminum foil and do not wrap other Petri plate. Now transfer both the Petri plates in LAF. Open the lid of unwrapped Petri plate. 
1.7  Now switch on UV light for 30 minutes.
1.8  After 30 minutes exposure, switch off the UV light & close the lid of unwrapped Petri plate.
1.9  Incubate both the Petri plates in incubator at 30-35ÂșC for 24-48 hours.
1.10  Prepare positive control by streaking Bacillus subtilis culture and negative control as it is without streaking.
1.11  Apply the same procedure for UV Light of other LAF & Pass Box. For checking Efficiency of UV Light of LAF of Sterility Room, do not perform the test in Sterility Room. For the test, the UV light of Sterility LAF should be fitted to MLT or Bioassay LAF.
1.12  After incubation observe the plates for total bacterial count. Record the results.

2.0  Precaution

2.1  Switch on the UV light after exposing the plates on the work station of the LAF.
2.2  Switch off the UV light before collecting the plates.

3.0  Frequencies

       Once in month

4.0  Abbreviation

SOP : Standard Operating Procedure
IPA : Isopropyl Alcohol
LAF : Laminar Air Flow
cfu : Colony forming unit
SCDA : Soybean casein digest Agar
Ankur Choudhary is India's first professional pharmaceutical blogger, author and founder of Pharmaceutical Guidelines, a widely-read pharmaceutical blog since 2008. Sign-up for the free email updates for your daily dose of pharmaceutical tips.
Email: .moc.enilediugamrahp@ofni Need Help: Ask Question


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