What are the best practices for preventing contamination in laboratory samples and reagents?

1 Personal hygiene

One of the most common ways to introduce contamination in laboratory samples and reagents is through your own body. Your skin, hair, saliva, and clothing can carry microorganisms, dust, chemicals, and other contaminants that can affect your experiments. To minimize this risk, you should always wear appropriate personal protective equipment (PPE), such as gloves, lab coats, goggles, and masks, and change them frequently. You should also wash your hands before and after handling samples and reagents, avoid touching your face, hair, or mouth, and keep your nails short and clean.

2 Laboratory environment

Another source of contamination in laboratory samples and reagents is the laboratory environment itself. The air, water, surfaces, and equipment can harbor contaminants that can interfere with your assays and analyses. To prevent this, you should keep your laboratory clean and organized, and disinfect your work area before and after each experiment. You should also use filtered or distilled water for reagent preparation and rinsing, and avoid using tap water or ice that may contain impurities. You should also store your samples and reagents in appropriate containers and conditions, and label them clearly and accurately.

3 Sample handling

The way you handle your samples can also affect their quality and integrity. You should always use sterile and disposable pipette tips, tubes, plates, and other consumables, and avoid reusing them or sharing them with others. You should also use proper pipetting techniques, such as pre-wetting the tip, expelling the air, and dispensing at an angle, to ensure accuracy and avoid cross-contamination. You should also aliquot your samples and reagents into smaller volumes, and use them as soon as possible, to prevent degradation and contamination.

4 Reagent preparation

The reagents you use for your experiments can also be contaminated or degraded if not prepared and stored correctly. You should always follow the manufacturer's instructions for reagent preparation, and use fresh and high-quality chemicals and solutions. You should also check the expiration dates and appearance of your reagents, and discard them if they are expired, cloudy, discolored, or precipitated. You should also avoid adding or removing reagents from the original containers, and use separate pipettes and bottles for each reagent.

5 Equipment maintenance

The equipment you use for your experiments can also introduce contamination in laboratory samples and reagents if not maintained properly. You should always clean and calibrate your equipment regularly, and follow the manufacturer's guidelines for operation and troubleshooting. You should also check for any signs of contamination, such as leaks, spills, stains, or odors, and report them immediately. You should also use appropriate filters, liners, and covers for your equipment, and replace them as needed.

6 Quality control

The last but not least best practice for preventing contamination in laboratory samples and reagents is to perform quality control (QC) checks and validations for your experiments. You should always include appropriate controls, such as blanks, standards, and positive and negative controls, to monitor the performance and accuracy of your methods and reagents. You should also compare your results with expected values and ranges, and look for any outliers or inconsistencies. You should also document and record your procedures and results, and review them regularly for any errors or deviations.

7 Here’s what else to consider

This is a space to share examples, stories, or insights that don’t fit into any of the previous sections. What else would you like to add?