Bioburden Testing

Nelson Labs: A Full, Life-cycle Microbiology Testing Lab

Nelson LabsNelson Laboratories is a leading provider of full, life-cycle microbiology testing services for the Medical Devices, Pharmaceutical, Tissue and Natural Products industries. While we are known for exceptional quality and rigorous testing standards, we are also keenly aware of the bigger picture. It’s what we call The Science of Success™.

At the MD&M West 2016 trade show, Jeffery Nelson was asked to explain who we are and what we do. Watch this video to see what he said.


Nelson Labs Experts Invited to Present at Joint Conference

Thor Rollins, consulting manager, and Audrey Turley, research scientist, have been invited to speak at the joint conference of the Association of Analytical Communities Southern California Section (AOAC SCS) and Food and Drug Agency (FDA) 2016 Spring Conference. Rollins and Turley will be presenting the morning of Wednesday, April 27 at Chapman University, School of Pharmacy, Irvine. Click here for the full agenda.

DSC01871Rollins will be presenting on the application of chemical characteristics to medical devices. His presentation will cover how the industry is taking extractible and leachable applications and applying them to medical devices. The discussion will focus on what the challenges are, what benefits they have, where we are right now with the program and speculate about what these applications mean to the future of medical devices.

“I am excited for the opportunity to contribute to the discussion with colleagues and FDA experts about the future of the science behind biocompatibility and medical devices,” said Thor Rollins.

Turley will be presenting on in vitro alternatives to traditional animal testing. Specifically, she will be talking about in vitro irritation, sensitization and thrombogencity.

Visit the Nelson Labs website to view recent presentations by Rollins, How to Use Biocompatibility to Evaluate Changes in Medical Devices, and Turley, New Approaches to Assessing Biocompatibility for Medical Devices.

Tribute to Dr. Scott Sutton; Review of Bioburden Contamination Control

Scott Sutton, PhD, was a well-respected and influential thought leader in the microbiology industry. He was a consultant and trainer in CGMP, investigations, environmental monitoring, and contamination control for pharmaceutical companies for over 30 years. He gave many presentations on these topics, and received multiple awards for his publications in microbiology journals and industry trade publications. For the past 22 years, Dr. Sutton served on the United States Pharmacopeia committee on Microbiology, serving as Vice-Chair from 2000 through 2010.

Dr. Sutton passed away on October 19, 2015. Shortly before his passing, Dr. Sutton published an article regarding the process of controlling bioburden contamination in a manufacturing facility. In memory of this great contributor to the microbiological and pharmaceutical industries, we have highlighted a few key points from this recent article. To read the full article by Dr. Sutton, please click here.

Bioburden contamination is an aspect of product manufacturing that must be considered for all medical devices and pharmaceuticals. Processes to attempt to control the contamination through validations and monitoring in each phase of production should be in place to ensure the bioburden contamination remain at an appropriate level. Maintaining control of the bioburden is far too complex for a single individual or even department to accomplish by themselves, so training and adherence to these processes is vital in ensuring any bioburden contamination stays at a manageable level.

Building Design & Control: Bioburden control in a facility should optimally begin with the design and construction of the building. Areas in a facility that are able to be tightly controlled should be surrounded by areas that are not as easily controlled. An important part of this design is the placement of air filters to ensure the pressure differential between areas allows the aseptic air to be pushed out. An argument can be made that the placement of filters in a terminal location allows for better air cleanliness, however, the ease of monitoring and maintenance should also be considered when placing filters. Facilities should also be designed to prevent personnel and materials from using the same paths to minimize cross-contamination. This type of building design works best when airlocks and pass-through chambers are put in place, as they help maintain bioburden barriers.

Water Systems: The water system of a facility also contributes to the control of bioburden contamination in a building. The properties of water make it an easy avenue for microbial contamination. Because water is often used as a raw material and a utility, frequent maintenance and monitoring are necessary to contain the bioburden resulting from the use of water. The last design element Dr. Sutton discusses is the location of the product when it will be at its most vulnerable point in the manufacturing process. Protection of the environment around the product at this point by an isolator or other environmental controls aids in maintaining control of the bioburden.

Equipment: Once the design of the facility is in place, the next factor to analyze is the equipment being used. In addition to the tasks the equipment is required to perform, the ability to clean and sanitize the equipment should also be considered. Choosing equipment and placing it in locations that allow for easy cleaning and sanitation aids in the exclusion of microorganisms from coming in contact with the product. Fill lines and equipment should also be organized in a way that will not allow for mix-ups or cross contamination between filled products and raw materials. One way to minimize contamination is to eliminate the human factor, and utilize equipment to fill the product.

Cleaning Processes: The sporicides and sanitizers that are used in bioburden control processes need to be tested to show their efficacy against the microorganisms in a facility; generally, this is a four-step process. The first step is a suspension test. This test analyzes the effectiveness of a sanitizer against indicator organisms as well as other organisms found in a facility. This test aids in selecting the best sanitizer for your product and also determines the most resistant microorganism. The second step is a coupon study, performed on materials present in the facility. This study evaluates the effectiveness of the chosen sanitizer against the organisms found in the suspension test. The third step is a “mock” sanitation study to provide real-world analysis of the effectiveness of the sanitizer. The last step of testing the sanitizer is ongoing environmental monitoring. This is usually done by the annual trending of the environmental monitoring to show the bioburden is being adequately controlled.

Personnel: The main source of bioburden contamination during manufacturing process comes from the personnel involved. It is estimated that an individual at complete rest sheds about 10,000 particles per cubic meter. Any movement or activity increases this number exponentially. Because of this, it is important to be careful in selecting gown material and also gowning methods. Simulated trainings, proficiency testing, and monitoring of the operators and their involvement in the manufacturing process are vital to make sure human contamination of the product is limited. Use automation in manufacturing to avoid the chance of mix-ups causing cross-contamination and limit the need for human intervention. To assist in monitoring the bioburden in these processes, bioburden testing should be performed on all material coming into a facility, and checked against existing bioburden acceptance criteria prior to use.

Process Monitoring: Monitoring activities and processes to control bioburden are indirect, so it is important to partner with a reputable testing facility that is knowledgeable on current industry standards in creating and carrying out these procedures. USP has recently released a chapter to help break down laboratory operations into a series of systems, that when paired with other USP chapters are useful in determining the best practices for a facility.

Thank you, Dr. Scott Sutton, for your contribution to the microbiology community.


Need Additional Guidance? Nelson Labs employs many scientists who actively participate in the creation and modification of industry standards who can help interpret the standards and apply them to specific products and facilities.


Nelson Laboratories Scientist Provides Clarification on Tissue Bank Cleaning Validations

Alpa Patel, Nelson Laboratories Senior Scientist - Healthcare Reprocessing

Alpa Patel, Nelson Laboratories Senior Scientist – Healthcare Reprocessing

Nelson Laboratories, Inc. Alpa Patel, senior scientist in healthcare reprocessing, presented at the annual American Association of Tissue Banks (AATB) meeting last month on the topic of Equipment Cleaning and Disinfection Validations, something she calls, “the tissue industry’s compliance challenge.

Highlighting regulatory issues and solutions for process validations at tissue banking facilities, Patel noted, “Because tissue is an emerging industry they have had less experience with validations than other MedTech service providers and may not know what to expect.”  However, recent regulatory attention on the cleaning, disinfection, and sterilization validations for the equipment and supplies used to process tissue is changing that.

“While the FDA does not clearly state the requirements for these validations, recent trends have shown that companies that state they adhere to the American Association of Tissue Banks (AATB) standard may be required to have a validation plan in place.” said Patel. “And although the Good Tissue Practices (GTP’s) do not specify these validation practices, there is good reason for tissue banks to acquire them.”

Intimately involved in assisting some of the world’s premier tissue banks in establishing their validation plans, Patel recommends tissue banks review whether or not an equipment validation plan is in place and take appropriate measures to ensure compliance sooner rather than later since:

  • Regulators have begun auditing some tissue banks.
  • Facilities that did not have validation data to support the cleaning, disinfection and sterilization of their equipment have been issued observations.

Patel reminds us “The real value of a process validation for equipment used in tissue processing is that  validated cleaning, disinfection, and sterilization processes help ensure the absence of cross contamination between donors during tissue processing.”

To learn more read Equipment Cleaning, Disinfection, and Sterilization Validations – The Tissue Industry’s Compliance Challenge!, and Importance of Cleaning and Sterilization Validations, Even When They May Not Be Required.

You may also contact Nelson Laboratories at, 800-826-2088, or

Updates to the Bioburden Standard ISO 11737-1; Significant Additional Guidance. P.S. What Happened to the Microbiologists?

Did you miss MD&M Texas? Check out the Tech Theater presentation given by Nelson Laboratories scientist Martell Winters. As biological and tissue products and combination products become more prevalent, new questions are often asked related to microbiology that are different from those asked for traditional medical devices.  As these questions become more common, additional guidance is necessary for the industry.  Much of this additional guidance will be added to the new version of the ISO bioburden standard, 11737-1.  Some of this information must be added due to the lack of microbiological expertise in the industry.  However, when the information is added it will not be easily understood by non-microbiologists, meaning that some understanding must be present to fully appreciate it. Following are some main points to be added to the standard which will be discussed in the Tech Theater presentation.  Also some discussion will be provided regarding the microbiological expertise in the medical device industry.

  • Low bioburden products
    • How low is low?
    • Why are they different?
  • How should the bioburden test be performed?
    • Review of raw materials/manufacturing process
  • Optimization of bioburden testing
    • Increasing sensitivity (e.g. volume factors)
    • Pooling of bioburden samples
  • Reviewing bioburden data
    • Addressing TNTC values
    • Addressing spreaders/lawns

Importance of Cleaning and Sterilization Validations, Even When they may Not be Required

By Alpa Patel, Department Scientist-Healthcare ReprocessingCleaning-Process

I recently attended the 10th Annual FDA and Changing Paradigm for HCT/P Regulation Conference, with my colleague Wendy Wangsgard, Department Scientist, Bioburden. We presented topics of interest that have surfaced the validation realm, in addition to learning updates from the FDA.

At this conference, the FDA presented new R&D data on new developing assays, news on current and retired tissue establishments, and important events that occurred during the last year within the tissue industry. These updates include reviews of tissue products, recalls and information on how to prepare a response to recalls.

My presentation focused on cleaning validations on equipment and supplies used for tissue processing. This included when validations are needed and why it is important to perform even if the FDA does not require these validations at this time.

The two key points when a validation is essential are:

  • When a new process is introduced: It is necessary to validate new processes to ensure the procedure is adequate for cleaning and sterilizing.
  • When there is a change to the process: Changes to the process can include steps of the process, a change of disinfectants/detergents, and new equipment.

Validations are necessary to ensure the process is effective and all equipment and supplies are free of contaminants after the cleaning process. Validating also ensures consistent process capability, meaning each time a device is cleaned, you know it is consistently cleaned to the required and safe level.

Cleaning validations are important, even when not required, to ensure safety through cleanliness. Validating the cleaning, disinfection and sterilization processes lowers the risk of cross-contamination between donors since the tissue-processing equipment and supplies that are used between donors are clean and sterile.

Validations for sterilization and cleaning, while not always required but are extremely important for manufacturers to consider. Validations are one more step that helps ensure the safety of the reusable equipment and supplies used to process donors every day.

Other highlights from the conference include:

  • Details from the FDA’s Draft Guidance Document
  • Classifications for recalls
  • Guidelines for adverse reaction reporting
  • How to prepare an FDA response