How to clean laboratory material correctly
— Equipo JP Selecta
In any analytical or diagnostic environment, the quality of the results depends on the reliability of the data, but that data depends on the purity of the container. When a test fails or shows an unexpected deviation, we usually look for the cause in the purity of the reagents or the calibration of the measuring instruments. However, most real errors originate in invisible cross-contamination.
Keeping a laboratory clean is a critical step that directly conditions any subsequent procedure. Learning how to clean laboratory glassware and equipment scientifically and systematically is essential to protect the integrity of your analyses and extend the working life of your tools.
→ You may be interested in: How to improve laboratory efficiency
How to clean laboratory material according to the type of residue
A very widespread technical error is to assume that a universal washing method exists. Treating every utensil with the same soap and the same water temperature is the perfect recipe for fixing contaminants rather than removing them. The washing protocol must be selected specifically according to the chemical or biological nature of the residue present on the surface.
Cleaning chemical residues in the laboratory
Handling acids, strong bases and organic solvents requires a prior neutralisation phase and specific rinses before subjecting the items to general washing. In this category, the nature of the structural material is decisive.
Components made of PTFE (Teflon) and borosilicate glass stand out for their excellent chemical inertness, tolerating without any difficulty the use of aggressive cleaning agents, acid solutions or degreasing bases.
By contrast, low-density plastics or certain elastomers and seals suffer structural degradation, cracking or absorption of chemical traces if exposed to pure organic solvents, which can lead to the subsequent leaching of compounds in future analyses.
Biological and protein residues
One of the most important points in understanding how to clean laboratory material, because of a poor choice of water temperature. Applying hot water directly to material contaminated with blood, serum or culture media is a critical error: heat denatures proteins instantly, causing them to coagulate and binding them firmly to the walls of the vessel.
The correct order is unavoidable: first a thorough flush with cold water, then a specific enzymatic detergent to break up the peptide chains and, finally, thermal rinsing.
Greasy or paraffin residues on laboratory instruments
Oils, lubricants and paraffin are common contaminants in quality control laboratories and, very specifically, in histology areas. Because of their hydrophobic nature, water and conventional soaps cannot remove them in a first phase. These residues require the use of specific organic solvents or degrading thermal baths before moving on to aqueous cleaning.
Maintaining a clean workflow on these instruments is vital if we work continuously with specialised histology equipment, such as flotation baths or J.P. Selecta tissue processors, where the build-up of external residual waxes can compromise the accuracy of mounts and the general cleanliness of workstations.
| Type of residue | Agent / method | Compatible materials | Error to avoid |
|---|---|---|---|
| Chemical (solvents, acids, bases) | Neutralisation and specific rinsing according to the agent | PTFE and borosilicate glass tolerate aggressive agents better than low-density plastics or elastomers | Using the same agent for all materials without checking compatibility |
| Biological / protein | Cold-water flush, enzymatic detergent and thermal rinsing at the end | Material in contact with blood or culture media | Using hot water directly, since it fixes the protein to the material |
| Greasy / paraffin | Specific solvent before aqueous washing | Common in histology and media preparation | Washing with water before dissolving the grease |
Cleaning is not the same as disinfecting or sterilising
In everyday laboratory jargon these three terms are often used as if they were synonyms, which creates serious operational confusion. When we talk about how to clean laboratory material we must distinguish between disinfecting and sterilising.
All 3 represent completely different levels of microbiological decontamination:
- Cleaning: This consists of the physical removal of visible dirt, organic matter and chemical residues by mechanical action and detergents. It does not destroy microorganisms, but it is the prior and indispensable condition for any subsequent process to work. Without thorough cleaning, the remaining dirt will protect germs from the action of disinfectants.
- Disinfection: This significantly reduces the load of living microorganisms on a surface or tool by means of chemical (disinfectant) or thermal agents, but it generally does not destroy the most resistant bacterial spores. It is a sufficient level for maintaining work surfaces, stainless steel benches and material classified as non-critical.
- Sterilisation: This is the absolute level of biological safety. It consists of the destruction or total elimination of any form of microbial life, including viruses, fungi, bacteria and their spores. It is mandatory in microbiology and cell culture environments, or when instruments come into contact with sterile tissue.
→ If you are wondering how to sterilise laboratory material effectively under validated workflows, the industry standard is to sterilise in an autoclave using saturated steam under pressure to guarantee the total thermal death of any pathogen [See JP Selecta Autoclaves].
Common mistakes in laboratory cleaning
Knowing how to clean laboratory material means understanding the process and its consequences.
To genuinely optimise workflows and avoid repeating tests because of false positives or chemical contamination, you should audit your staff to make sure they do not make these common mistakes:
- Applying hot water prematurely to proteins: As we have highlighted, this fixes the biological residue to the glass or plastic instead of flushing it away, complicating its subsequent removal.
- Standardising the washing protocol for all components: Treating a flexible plastic Falcon tube in the same way as a borosilicate glass volumetric flask compromises the working life of the plastic and can generate contamination from poorly rinsed detergents.
- Storing material without absolute drying: Storing containers with traces of residual moisture encourages the development of a damp microclimate, ideal for recontamination by environmental fungal spores, invalidating the earlier effort to keep instruments sanitised.
- Reducing contact times with the detergent: Clinical cleaning agents and chemical solvents need minutes of direct exposure to break the molecular bonds of contaminants. A quick, immediate rinse leaves a residual film invisible to the naked eye that will distort future spectrophotometric or volumetric analyses.
Now that you know how to clean laboratory material correctly, it is important to periodically review both the condition of the instruments and the cleaning, disinfection and sterilisation protocols applied in your laboratory. A well-defined routine reduces the risk of cross-contamination, improves the reproducibility of results and extends the working life of the equipment.
At J.P. Selecta we have spent decades developing equipment, instruments and accessories for research, quality control, microbiology, histology and other scientific laboratories. Our aim is to offer reliable solutions that help maintain safe, precise and efficient processes day to day.
If you would like to know more about our equipment or need advice on choosing the most suitable solution for your laboratory, we will be delighted to help.