Cleaning of Glassware for Microbiological Testing

1.0 Objective

To establish a comprehensive procedure providing guidelines for effective cleaning and preparation of various types of glassware used for microbiological testing and analysis in the laboratory.

2.0 Scope

This SOP applies to the cleaning of all reusable glassware including petri plates, pipettes, flasks and test tubes utilized for any microbiological tests, media preparation, and culture maintenance performed in the Microbiology Laboratory of the Quality Control Department.

3.0 Responsibility 

3.1 Lab assistant is responsible for cleaning of glassware as per the procedure

3.2 The Microbiologist is responsible for ensuring this procedure during cleaning of glassware.

3.3 The Head of Department / immediate supervisor is responsible for ensuring compliance with this SOP.

4.0 Accountability

The Head of Quality Assurance & Quality Control is accountable for ensuring this SOP is effectively implemented and that all laboratory personnel are trained on the requirements.

5.0 Procedure

5.1 Cleaning of Test Tubes

5.1.1 Remove and discard any contents from the tubes. Rinse tubes with tap water to remove any residual material.

5.1.2 Prepare a soap solution by diluting 1 ml liquid soap per 100 ml water (1% v/v concentration) in a large tub or sink. Immerse tubes fully in the soap solution for a minimum of 30 minutes to allow soaking.

5.1.3 Remove tubes from soap solution. Scrub and wash each tube thoroughly with tap water to remove all soap residues. Dip and rinse the cleaned tubes in Disinfectant solution.

5.1.4 As a final rinse, use freshly collected distilled water to remove any remaining particulates.

5.1.5 Place cleaned tubes in a drying oven set to 160°C and dry for 2 hours before use or storage.

5.2 Cleaning of Petri Plates 

5.2.1 Carefully remove any agar media or sample residues from the petri plates using precaution and collect in to a Biohazard bag.

5.2.2 Immerse petri plates in the 1% v/v soap solution prepared as in 5.1.2 and soak for 30 minutes.

5.2.3 Remove plates and wash thoroughly with tap water, ensuring soap is fully rinsed away. Dip and rinse the cleaned Petri plates in Disinfectant solution. Follow with a final rinse in distilled water.

5.2.4 Place cleaned petri plates in the autoclave or dry heat oven and sterilize as per the SOP for sterilization of glassware.

5.2.5 After sterilization, store petri plates in the microbiology section in a manner preventing recontamination.

5.3 Cleaning of Pipettes

5.3.1 Rinse pipettes with tap water first to remove any residues. Then immerse fully in the 1% soap solution for 30 minutes.

5.3.2 Remove pipettes one-by-one and wash the internal barrel thoroughly by pipetting tap water through the pipette repeatedly until fully clear of soap. Follow by pipetting hot water to ensure all soap residues are eliminated. Dip and rinse the cleaned Pipettes in Disinfectant solution.

5.3.3 Give a final rinse on the exterior and interior of the pipette using freshly collected distilled water.

5.3.4 Hang pipettes upside down or place in a drying oven/oven as per the approved drying SOP for that glassware.

5.4 Cleaning of Flasks

5.4.1 Discard any contents from the flasks. Rinse with tap water to remove any residual material.

5.4.2 Prepare a soap solution as per 5.1.2. Immerse flasks fully in the soap solution and soak for a minimum of 30 minutes.

5.4.3 Remove flasks from the soap solution. Scrub and wash each flask thoroughly with tap water to remove all soap residues. Dip and rinse the cleaned flasks in Disinfectant solution.

5.4.4 Use freshly collected distilled water for a final rinse to remove any remaining particulates.

5.4.5 Place cleaned flasks in a drying oven set to 160°C and dry for 2 hours before use or storage.

5.6 Cleaning of Other Glassware

5.6.1 For any other reusable glassware not covered above (e.g. volumetric flasks, beakers, measuring cylinders), follow the basic steps of soaking in 1% soap solution, scrubbing with tap water, rinsing with disinfectant and distilled water, and drying as per the prescribed method for that glassware type.

5.6.3 Sterilize applicable glassware as per the SOP for sterilization before further use.

6.0 Precautions

6.1 Wear appropriate PPE including heat-resistant gloves, lab coat and goggles when handling hot water, glassware and drying ovens.

6.3 Ensure soap is thoroughly rinsed from all glassware before drying/sterilization.

7.0 Abbreviations

SOP: Standard Operating Procedure

PPE: Personal Protective Equipment

QA: Quality Assurance

QC: Quality Control

SS: Stainless Steel

 

 

•      Author:  Bhavana Tatineni
•     Qualification: MSc Microbiology