4 tips for preventing cross contamination in the lab

October 21, 2022

Cross contamination in the lab can spread easily in the laboratory environment, resulting in implications for the validity of work carried out, sample integrity, as well as general health and safety.

In this blog, we explore how to avoid cross contamination of chemicals in the lab, including the clear labelling of containers and their contents and regular cleaning and sterilization of work surfaces.

1) Cleaning and sterilizing work surfaces

When it comes to laboratory cleanliness, it must be thorough and effective.

How cleaning solvents are stored and dispensed itself can have a significant impact. Wash bottles such as the AZLON® Round Integral wash bottle, which is designed with an integral spout and precision tip can be used safely and efficiently - minimising contamination as the inner tube doesn’t need to be removed and placed on the workbench when the bottle is refilled.

Another option is the AZLON® Wide neck wash bottle, which is specifically designed for easy and spill-free filling, reducing the amount of unnecessary mess and clean-up on your workstation. All bottles can be customised for easy identification, whether it's for water, acetone, methanol or other solutions.

Keeping the laboratory clean is the responsibility of all the people who work in there and a few guidelines to help are detailed below.

  • Clean up any liquid or powder spills as soon as they occur. All laboratory spills should be treated as high priority as they can result in serious injury or danger to those around as well as contamination
  • Return all laboratory products in their correct place once used – it helps with overall efficiency and smooth operation of the laboratory
  • After cleaning glassware in particular, make sure it is safely stored to minimize breakages
  • Leave the workbench clean at the end of the day. It will save time the following day when work is resumed and reduce the chance of contamination impacting future processes

2) Avoiding Cross-Contamination through clear identification

It is also vital that sample collection and storage devices within the laboratory are labelled where appropriate to enable contents to be quickly and easily distinguished. Errors can be costly and jeopardise valuable work underway. Easy sample identification can be supported in a number of ways. It can be done by using colour coded caps, which can be used on storage vials for example, the use of barcoding as well as clear written labels on sample devices where appropriate.

DWK's Silicone Lids also make use of colour coding to provide a highly visual, identifiable way of covering laboratory containers of different shapes and sizes, especially containers that typically do not have associated lids or closures such as beakers or Erlenmeyer flasks.

3) Using protective equipment to protect work from cross contamination

Even when not handling hazardous materials, it’s best practice to wear gloves. They can help protect your skin from chemicals or other hazards you handle, and in some instances, they can also be used to protect the work from contamination. After use, gloves should be removed, appropriately disposed of, and replaced with a fresh pair, further reducing the risk of contamination in the lab.

Laboratory hoods (laminar flow, biosafety cabinets) are ventilation devices that are also used widely in the laboratory to provide controlled areas of work to help protect both the laboratory personnel and the materials they are working with, especially when specific work depends on a sterile technique or involves pathogenic or other highly sensitive material that could be easily contaminated.

4) Wash, rinse, repeat!

When it comes to keeping on top of cross contamination in the laboratory a great mantra is clean well and clean often. Always clean appropriate laboratory equipment between uses, with frequent cleaning of work surfaces and other sterile areas part of this routine. Running regular autoclave cycles is also recommended to ensure sterilization of containers. To avoid the potential of contamination occurring ensure you follow relevant instructions for the autoclaving process itself, including the duration of the cycle and how to prepare equipment properly. Not all items can be autoclaved, especially plasticware made of polymers unsuited to autoclave temperatures. In this instance, a thorough cleaning process should be undertaken instead.