I mixed up two labels last week and caught it only by luck. Every tube and slide that passes my station is somebody's diagnosis, and my hands aren't sure enough yet. I slow down to be careful and then the rack backs up and I speed up and make another slip. I go home replaying every label, hoping I didn't send someone the wrong answer.
More people experience this than they realize.
You keep making mistakes handling specimens, and each one could harm a patient.
If this sounds familiar, the Library can help you find the bigger picture.