Jennifer Hawkins Randle, MSHA, CLC(AMT)

The pre-analytical phase is viable in every aspect of a healthcare professional career. As laboratorians, we depend on phlebotomists for most of our preanalytical phase. It is not just the phlebotomists that the lab depends on for quality specimens. We depend on physicians and nurses to follow protocols and provide a “good” specimen. Most of all, we depend on other laboratorians that we collaborate with to provide a quality sample when follow-up testing must be performed by another laboratory.

The purpose of this article is to bring increased awareness to the vital seriousness of a QUALITY specimen collection and timely submission when results are used for patient assessment, diagnosis, treatment, and/or monitoring.

This is the events of what happened when our lab received a sample for BRUCELLA Rule–Out(R/O), on or about the fourth week after initial subculture. The specimen was received on a blood agar plate (BAP), but at first look, it was thought to be a chocolate plate (CHOC) due to the age of the plate. Now, Brucella is a fastidious, aerobic, small gram-negative coccobacillus that is neither motile nor spore forming. Brucella is considered an overlap select agent because it not only has the potential to pose a threat to public health and safety, but it also poses a threat to animal and animal products.

Polymerase chain reaction (PCR) is a time-consuming process and the suspected organism is easily airborne, so we eliminated having to go into the sample multiple times. Therefore, we performed PCR simultaneously with the Gram stain. The lead Medical Laboratory Scientist (MLS) on this case re-subbed and performed biochemical tests and made a Gram stain. The biochemical tests correlated with the suspected organism. It was not until the Gram stain was performed that we noticed a problem. The lab supervisor re-stained and viewed the slide and concluded with the lead MLS that the Gram stain showed Gram-positive cocci clusters, which is not consistent with Brucella species. However, PCR results indicated Brucella species.

The initial Gram stain threw the whole case off! From this, it is evident that Staphylococcus overgrowth contamination masked the ability to get a pure culture of the Brucella that was detected by PCR. This catalyst made me finally decide to focus on the importance of the pre-analytical stage of clinical laboratory testing. Once again, this confirms results are only as good as the specimen submitted.

An article published in a 2012 report by Bonini and his colleague supports these findings. They found that preanalytical errors predominated in the laboratory, ranging from 31.6% to 75%.1 Out of the three stages of medical testing, current studies show the pre-analytical phase accounts for 46% to 68.2% of errors observed during the total testing process.2 Any error during the laboratory testing process can affect patient care, including delay in reporting, unnecessary redraws, misdiagnosis, and improper treatment. Sometimes these errors can be fatal (e.g. acute hemolytic reaction after incompatible blood transfusion caused by an error in patient identification).3 While there are many published protocols written to minimize errors, along with how to measure those protocols; a practical solution would be to do “random” monthly direct inspections. In short, inspect what you expect. 

Until the science of error prevention catches up with the need that exists, the best we can do is adopt common-sense steps that address the most common and important factors known to contribute to diagnostic error and harm,2 which are preanalytical errors.

In conclusion, the MLS “not” immediately recognizing the “original” collection dates, caused more hands-on than what was needed. Quality of the submitted specimen was poor and overgrown. A four-week-old sub-culture plate should not have been submitted. The receiving laboratory should have noticed the “original” date. However, it was reasonable for the receiving lab to think the specimen was suitable for testing.

With the variation in percentage of errors remaining close in proximity over a 2-year period (32%-75% vs 46%–68%), it is so important for laboratorians to recognize our integrity and our profession must be pledged to the absolute reliability of quality work. We must conduct ourselves at all times in a manner appropriate to the dignity and standards of our profession. In short, we must be the gatekeepers of accurate and precise patient results. Furthermore, this case demonstrates the importance of effective communication and cooperation between laboratorians.


  1. Hammerling Julie A. A Review of Medical Errors in Laboratory Diagnostics and Where We Are Today; Laboratory Medicine 2012; 43(2): pp 41-44
  2. National Patient Safety Foundation Reducing Diagnostic Error | Patients and Families. 2014
  3. Kaushik, N and Green, S. Pre-analytical errors: their impact and how to minimize them. MLO 2014