You’re working late in the lab one day, open the liquid nitrogen Dewars, and pull out a box of vials containing cell lines of various passage numbers, only to find that several tubes are so poorly labeled that you cannot make out what type of cell line it is at all. The tube is located next to other vials of the cell line you want and is marked with the desired passage number. So, should you use the mislabeled specimen? What is a scientist to do in such circumstances?
First, notify the right people
Not all specimens are created equal; some samples might be used as controls in a small, less critical test run, while others contain irreplaceable cells from patient biopsies. Regardless of the sample type, it is always important to notify the appropriate people when a mistake in the lab is made, especially regarding sample identification. For experimentation, mislabeled specimen are most likely to yield skewed results, which means potentially repeating the experiment unnecessarily, utilizing more time and money. If reagent containers are involved, it is crucial others are aware of the mistake, so they can avoid repeating it using the same reagents. For patient specimens, the error must be communicated as soon as possible to ensure that proper mechanisms are in place to inform the patient and to immediately assess the steps necessary for re-obtaining the sample, if possible.
Attempt to re-trace and re-label the specimens
Once a sample is identified as mislabeled and the right personnel is notified, it’s often possible to re-trace and/or re-label the sample. However, re-tracing samples can be tricky, especially when utilizing older methodologies like handwritten notebooks. To optimize the chances that samples can be re-identified, it’s recommended to implement electronic tracking methods, such as a laboratory information management system (LIMS) combined with barcode and/or RFID labels. From the start, a LIMS-based system will minimize the number of potential errors, but re-tracing them is also made simpler with specific identifiers assigned to each sample and container. Implementing a LIMS that tracks sample placement can help with this, as can utilizing systems that include two methods of tracking specimens. For instance, barcodes can be combined with human-readable text so that the sample can still be identified if a barcode fails. Similarly, for more automated systems, RFID can be combined with barcodes, such that both can be used on nearly any type of label using just one printer. That way, if the RFID reader fails to read your samples, the barcodes can be scanned instead.
Review what went wrong and correct it
It’s as necessary to review and correct what led to the mislabeled specimen as it is to remedy the situation when it immediately occurs. Long-term planning is essential for any lab, and to plan effectively, labs must remain an open environment where problems, no matter who is at fault, can be discussed freely.
When addressing the situation, consider all factors that might have played a role in the error. These can include:
- Overall method of sample identification: Is a temporary label initially used or written by hand with a permanent specimen label to be affixed at a later point in the process (secondary labeling)?
- Type of label used: Is the proper label being used based on the container and the environmental conditions it will encounter?
- Label printout used: Is all relevant information provided on the label? What about barcodes?
- Sample identification SOPs: Are the proper specimen labels affixed to the collection tube immediately after specimen collection
- Sample procurement SOPs: Are multiple specimens collected prior to receiving the final test order without being labeled?
- Administrative factors: Are labeling policies and procedures made clear to staff, with documentation readily available upon request?
- Personnel training: Are all personnel appropriately trained on the correct labeling procedures to follow?
- Lab communication: Are the lines of communication in the lab kept open, with staff encouraged to divulge any errors discovered?
- Experimental/analytical workflow: Do you use a LIMS or inventory management software to ensure efficient experimental workflow?
Remember, the goal should not be to assign blame but to identify where human errors are introduced and to design strategies to mitigate them. Every lab will encounter an error eventually; minimizing this rate should be what every lab strives for, using common sense and well-designed tools and protocols.
LabTAG by GA International is a leading manufacturer of high-performance specialty labels and a supplier of identification solutions used in research and medical labs as well as healthcare institutions.