What Happened?

During their first day in the lab, a postdoctoral researcher was preparing frozen human tumor xenograft samples for metabolite analysis using a single-blade razor. After processing each sample, they placed the razor directly on the benchtop. When retrieving it for the next sample, they inadvertently picked it up by the blade instead of the handle, resulting in a laceration to the index finger. The researcher washed the wound, applied a dressing from the laboratory's first-aid kit, and sought medical attention due to the potential for exposure to bloodborne pathogens.

What Was The Cause?

Because it was their first day in the lab, the postdoc was unable to locate the tool typically used for this procedure and was not yet familiar with the group's sharps-handling protocols. They selected a single-blade razor in place of a disposable scalpel and reused it across multiple samples. By the time of the injury, they had already processed several samples and had become habituated to the task, reaching for the blade without looking closely. The underlying causes included a hazard recognition gap, missing controls, and a technique-level error.

How can incidents like this be prevented?

• Replace single-blade razors with safer alternatives for tissue sectioning wherever feasible — disposable safety scalpels with retractable or shielded blades, or pre-loaded scalpel handles with blade-removal devices.
• Standardize on a single approved cutting tool for frozen xenograft processing across the group to eliminate ad hoc substitutions.
• Stock single-use, pre-sheathed blades in a clearly labeled, easily located supply drawer to remove the incentive to reuse blades across samples.
• Place a dedicated sharps disposal container within arm's reach of every tissue-processing station.
• Develop a written SOP for frozen tissue sectioning that specifies the approved tool, single-sample blade use, staging location between cuts, and disposal procedure.
• Require documented sharps-handling training and an SOP walkthrough before any new lab member handles blades — completed and signed off on day one, before independent bench work begins.
• Implement a first-week buddy system pairing new personnel with an experienced group member for any procedure involving sharps or biohazards.
• Add a "tool location" orientation to onboarding so new personnel know where standard equipment is stored and whom to ask before improvising.
• Suggest cut-resistant gloves (e.g., ANSI A4+ or equivalent) worn under nitrile gloves during blade handling and sectioning.

What to Know

Although these tumor samples were isolated from murine xenograft hosts, they are of human origin and must be treated as potentially infectious, as they may harbor viruses transmissible to humans.

Resources

• Establishing and Maintaining an Extensive Library of Patient-Derived Xenograft Models (2018)