In 2009, the European Network of Forensic Science Institutes (ENFSI), Scientific Working Group on DNA Analysis Methods (SWGDAM) and Biology Specialist Advisory Group (BSAG) organizations published a position statement requesting that manufacturers of disposable plasticware and other reagents for the forensic market take precautions to prevent contamination in their manufacturing processes(1)
A famous European case, dubbed the "Phantom of Heilbronn", prompted this call for action regarding quality. In this 15-year case, detectives searched for the identity of a female serial killer who left a trail of DNA over Germany, Austria and France. DNA evidence was collected from over 40 crime scenes. In March of 2009, investigators discovered that the female DNA was from a worker at a factory where cotton tips used to collect crime scene samples were produced. Over 16,000 hours of police work valued at more than 2 million Euros was wasted in pursuit of this serial killer.
"Promega meets or exceeds all of the relevant guidelines put forth by ENFSI, SWGDAM and BSAG to reduce the chance of human-to-product contamination."
The Phantom of Heilbronn is only one example of the impact DNA contamination can have on forensic investigations. In an effort to address the issue on a broad scale, ENFSI, SWGDAM and BSAG published the position statement to “…raise awareness and to encourage interaction between manufacturers and the forensic community… We propose that a new product grade be introduced for forensic applications…”. The article included a series of guidelines or recommendations for manufacturers to follow. The regent-specific guidelines include:
- Automation of manufacturing lines
- Minimal interaction of staff with manufacturing lines
- Adequate protection for staff who come into contact with products
- Positive-pressure airflow through a HEPA filter (Class 10,000 clean room standard or equivalent)
- Post-production quality control (QC) checks and process controls
We would like to share the processes that Promega has in place to comply with the proposed guidelines.
The Promega facilties in Madison, Wisconsin, are ISO13485-certified. This certification assures our global customers that Promega has established reliable and effective processes for product development, manufacturing, distribution and customer support in its quality management system.
At Promega, all employees involved in the Genetic Identity product line go through rigorous, ongoing training to maintain a high level of expertise and skill. We have a dedicated group of individuals from Research and Development, Manufacturing, Dispensing, Kit Packaging and Technical Services. All of these functions are carried out at Promega headquarters in Madison, Wisconsin, allowing constant collaboration between product development and manufacturing and a cohesive approach to technical support to respond to customer issues quickly and thoroughly.
Promega maintains full control of key raw materials from amidite manufacture through bulk reagent production. All oligonucleotides used in Promega products are synthesized on site in Madison, Wisconsin, using proprietary purification methods. In addition, our proprietary dyes are synthesized at our manufacturing facility in San Luis Obispo, California. QC testing for oligonucleotides includes analytical HPLC, capillary electrophoresis, mass spectrometry, pH and conductivity measurements, and UV spectrophotometry.
Promega understands the importance of separating pre- and post-amplification processes to protect our products and customers. We have created robust manufacturing and dispensing processes with supporting documentation to reduce the risk of contamination.
Only trained personnel are allowed to enter pre-amplification manufacturing suites, and those personnel are required to wear lab coats, safety glasses, hairnets, face masks, beard covers (if applicable) and gloves. Promega uses four pre-amplification suites when manufacturing pre-amplification bulk reagents.
The first suite is dedicated to the manufacture of buffers, master mixes and amplification-grade water. No DNA is allowed in this suite except for the dNTPs used to manufacture buffer or master mix. Critical in-process materials used in the production of buffers or master mixes have gone though quality control testing and are released by our Quality Assurance department prior to use in downstream manufacturing procedures.
The second suite is dedicated to the manufacture of primer pairs. All large-scale bulk production of primer pairs is completed in laminar-flow hoods. No DNA is allowed in this suite except for oligonucleotides synthesized on-site. Bulk oligonucleotides must go through quality control testing and release by our Quality Assurance department prior to use in primer pair manufacture.
The third suite is used for pre-amplification quality control setup and the manufacture of control DNAs for short tandem repeat (STR) systems. Many products are QC tested for human-to-product contamination, product yield, sensitivity and balance of amplified products using STR-typing methods. QC testing and full control of manufacturing and QC processes for all product components ensures lot-to-lot consistency.
The fourth suite is used for quality control setup of Plexor® reagents. Many Plexor® reagents are QC tested for human-to-product contamination, standard curve generation and product-specific amplification.
Promega has two 1.5ml dispensing lines that were customized to be compatible with the Promega-specific tethered tube cap and can dispense 11,000–12,000 tubes of reagent per day. On average, Promega dispenses 134,000 tubes of reagent per month. In addition, Promega has a bottle dispensing line that can dispense into 15–1,250ml bottles. This line can fill 10,000–12,000 bottles per 8-hour shift. To control airborne particulates, all automated dispensing equipment is contained within an ISO Class 8, environmentally controlled area, which is equivalent to Class 100,000. The rooms are constructed and used in such a way to minimize particulates by restricting access to trained staff who must follow written procedures and process controls, including those that control temperature, humidity and positive pressure in all rooms. Staff working within the environmentally controlled areas must wear lab coats, safety glasses, hairnets, face masks, beard covers (if applicable), foot covers and gloves. All pre-amplification reagents are dispensed within the environmentally controlled rooms.
Promega kit packaging staff is specially trained to work with Genetic Identity kits. Components and kits are handled on dry ice during the kit packaging process to ensure that our products do not go through a freeze-thaw cycle. Allelic ladder is packaged in a separate packaging department, where it is placed within a heat-sealed, tamper-evident pouch prior to final kit packaging. This step greatly reduces the chance of product-to-product contamination during the kit packaging process.
Promega uses a barcoded shipping system, allowing 99.5% accuracy on all shipped products. Extensive testing has been done to determine the amount of dry ice required to ensure that our products remain at the correct temperature for extended periods of time—for example, in the case of delivery delays, including delays in international customs.
In summary, Promega enforces stringent, built-in quality standards at each of the main manufacturing steps. By the time a product is released for sale, it has gone through at least three reviews by our Quality Assurance department, giving you confidence that reagents will perform according to rigorous requirements. Promega is dedicated to ensuring high-quality product free of both human-to-product and product-to-product contamination to our forensic customers. We will continue to monitor on-going discussions and decisions on the topic of quality and will work with leaders in the industry to establish and implement quality guidelines. In addition, Promega meets or exceeds all of the recommended guidelines put forth by ENFSI, SWGDAM and BSAG to reduce the chance of human-to-product contamination except for the recommended Class 10,000 clean room.