Cell Culture Incubators - They Sure Don't Make 'em Like They Used To

Cell culture incubators
Courtesy Esco

Incubators have been a mainstay of many applications in life science research and clinical testing for many many years. The term incubators can refer to a broad range of manufactured products, but let us narrow the focus of this article to equipment used for cell culture.

Equipment from decades ago was primitive when compared to what is available today. One early model sported all copper construction, not to impede contamination, but to enable its construction method using soldered seams. This particular water jacketed incubator was also heated by a gas flame and used a mercury filled temperature switch to control temperature within a few degrees of a setpoint.

Why were incubators water jacketed?

There were two valid design reasons for building a water jacketed cabinet. Early on, heating options were practically limited by cost and capability to the delivery of heat in concentrated areas. Since temperature uniformity throughout the work zone is probably the most important performance consideration for an incubator, it was necessary to evenly disperse the concentrated heat throughout the chamber in a manner that did not create undesirable variance. One way to accomplish this was, and still is for some manufacturers, to surround the chamber with a water filled "jacket". The water served as a heat distributor through natural convection.

The second reason for water jacketed design is to provide an interior environment with very little air movement. With all the chamber wall surfaces maintained at the same temperature, the heat input to the work space is uniform, and robust air circulation to provide an even temperature distribution is not needed. Air movement tends to promote desiccation in cell culture media, so lower air movement is generally better. Many cell culture operations also require very high levels of relative humidity, and lower chamber air movement will tend to promote a higher moisture level in the contained space. It was common to place a tray of water in the base of the chamber to saturate the air.

Not surprisingly, manufacturers continually strive to improve their products. New or improved technologies for measurement, control, or construction related to incubator design eventually reach a price point that enables their practical incorporation as a product improvement. Improved temperature controllers, sensors, and heater designs have enabled the production of incubators that deliver performance comparable or superior to water jacketed designs, but without the water jacket.

To grow, cells have the same needs today they had decades ago. Manufacturer's application of technological improvements to continually enhance their products has provided real benefits to researchers and other users of cell culture incubators. Higher reliability and lower requirements for attention from the user has increased lab efficiency.

Get more information about the useful features incorporated in the latest cell culture incubator designs from product specialists. Share your concerns and challenges with them, combining your own process knowledge and experience with their product application expertise to develop an effective solution.

CO2 Cell Culture Incubators from Atlantic Technology Group, Inc.

Environmental Chambers - Difference Between an Alarm and a Limit Control

Walk-in Controlled Environment Room
Courtesy Percival Scientific

Users of controlled environment equipment are generally not process control experts. The user's interest in the equipment is, and should be, focused on how it furthers their own work and effort.

Lab equipment that provides a temperature control function will often have an integrated heating or cooling means that is regulated by the unit controller. Controlled environment chambers, including benchtop, floor standing, and walk-in types often are provided with sufficient heating of cooling capacity to do damage to the equipment, the contained product or work materials, even surrounding spaces if allowed to run out of control. Why so much power? Designing a chamber of any size to provide fast recovery after a disturbance, like a door opening, will boost the capacity requirements for the heating and cooling portions of the system. Similarly, equipment with extended temperature range is likely to have expanded cooling or heating, and there are many other performance requirements that have the same impact on the unit capacity. The key element for placing this type of equipment in an occupied space is how malfunction resulting in uncontrolled operation of the environmental conditioning system is handled to prevent catastrophe.

An alarm is an annunciation of an adverse condition. Alarm function may be, and often is, provided as part of the temperature controller, utilizing the same device, same sensor. Alarms tell the operator something has gone wrong, is about to go wrong, or is currently going wrong. The nature of most alarms allows the user to set the conditions at which notification occurs. Additionally, some equipment provides options for how alarms are handled. Audio and visual indication are common features, and some equipment is provided with alarm relay contacts that can be connected to building management systems or other remote monitoring equipment. Whether an alarm will automatically reset if proper conditions are restored, or manual intervention is required to stop any alarm related activity once the alarm has occurred can also be different ways in which alarm functions are implemented by manufacturers. The overall range of alarm functionality combinations is extensive, with some equipment providing richer feature sets than others.

Alarms, in some controlled environment systems, are configured to take some sort of action to remediate the adverse condition. This activity is separate from the announcement of the alarm condition. While having corrective action taken by the control system may seem advantageous, and in some cases it may help prevent loss or damage to product contained within the environmental chamber, this is not true limit control action and is not the best practice for assuring safe operation of machinery with the capacity to do real damage to itself or surrounding spaces.

A limit control may appear at the user interface level to mimic the function of an alarm. There is a difference, though. Properly done, a limit control operates with total independence from any part of the regular temperature controller. The limit controller will be a separate device and not share any operating hardware with the temperature controller device chain. What does this mean for the user?

Relying on the temperature controller to respond to an adverse condition has some potential flaws. The temperature controller, or any of the components in the temperature control device chain, could be the root cause of the adverse condition through malfunction or outright failure. Reliance on a control circuit, likely with a malfunction of one or more of its components, to prevent further temperature excursion is not good practice. A properly designed limit control circuit does not rely on any of the components in the potentially failed circuit to stop heating or cooling.

Not all failures are a single event. Chains of failure can trigger, or one failure can expose the existence of another system weakness or failure that was previously undetected. Having a positive and independent means to reliably stop system operation is not costly to implement and can head off catastrophes resulting in substantial loss of time and money. Catastrophe, for an environmental chamber, can look like this...

• Freezing of product that should not be frozen
• Freezing and bursting of pipes in a walk-in chamber
• Destruction of work or product contained within a chamber due to excessively hot or cold temperatures
• Excessively hot temperature that activates a fire protection sprinkler head in walk-in unit

In essence, the purpose of an environmental chamber is to create and maintain a single condition at any point in time. There is only one way that things can go right, and countless ways they can go wrong. Having an independent watchdog controller that prevents the worst from happening is good practice. Share your controlled environment chamber requirements and concerns with an application specialist. The combination of your process knowledge and experience with their product application expertise will yield an effective solution.

Lab Planning - Everything is Connected to Everything Else

Each participant brings value to the lab planning process

Lab planning, whatever the scale, benefits from participation by specialists in the various facets of the project. Nobody knows everything, so collaboration and coordination are needed to balance and satisfy the wide array of jurisdictional, institutional, scientific, and other requirements that make up a successfully completed project.

Lab space is comparatively expensive to create or renovate. Architectural, mechanical, electrical, or other items will be incorporated into the space that may not have applicability to future use of the square footage other than as a laboratory. A long term view of the space dedicated to laboratory use and the incorporation of features and structures that can support that long term use can be beneficial.

What are some of the facets and drivers of the lab planning process?

Safety - Most are familiar with common laboratory safety and sources of hazard. Arranging the work areas and equipment, coordinating personnel movement, and other considerations can serve to reduce the potential for mishaps. The details are far beyond the scope of this article, but keeping safety in mind and a knowledgeable safety specialist on the planning team will deliver benefits every day the lab is in operation.

Productivity - The arrangement of workstations and equipment can have a cumulative impact on how much work gets accomplished in a given time frame. Productivity improvements are most often achieved in very small increments, many of which, combined, add up to real gains.

Ergonomics - Lab work can entail precise manipulation of instruments and tools, as well as visual inspection or interpretation of ongoing processes. Maintaining a level of technician comfort will promote productivity and safety, as well as reduce the potential for errors. Participants in the planning and design process knowledgeable and experienced in ergonomics can add to the overall success of the project.

Facilities and Utilities - Lab spaces often have unique requirements for electrical and mechanical services and support. It can be beneficial to make an attempt to accommodate potential future uses of the space for lab processes other than the initial intended use. Air supply and exhaust, electrical service, plumbing specialties, and more can be initially installed to support a variety of future endeavors. This foresight could avoid disruption of surrounding spaces and excessive cost to make changes in the future.

Budget - The budget drives stakeholders to place a value on almost every facet and detail of the project. A careful weighing of the benefits derived from every part of the design puts discipline into the process and can lead to a positive outcome.

A great plan arises from the combination of many participants. Share your laboratory planning challenges with experienced professionals, combining your own knowledge and experience with theirs to produce an effective solution.

Depyrogenation Ovens

Air flow profile of a cGMP depyrogenation oven
Courtesy Lytzen A/S

Manufacturers of pharmaceutical products intended for parenteral administration to humans are keenly aware of the stringent quality standards, production process challenges, and regulatory requirements impacting their work. One area that is common to all parenteral products is the delivery of pyrogen free finished goods, as determined by approved testing procedures.

Pyrogens are substances that produce a temperature rise, or fever. They are generally described as endotoxins or exotoxins associated with bacteria. The subject of pyrogens, their nature and source, is well beyond the scope of this article. The focus here is on how to rid them from pharmaceuticals, specifically the containers in which they may be shipped, stored, or handled.

The sterile and pryogen free bulk parenteral final product needs to be dispensed into appropriate containers for shipping, storage, then handling, right up to point where it is administered to the subject. The containers must be pyrogen free, just like the product, in order to avoid any contamination. One way to accomplish this is with a heating process that assures destruction of pyrogens while protecting the processed items from other sources of contamination.

Of course, only items that can tolerate the necessary processing temperatures without destruction can be heat processed. The majority of dry heat processed items will likely be glass containers. A typical depyrogenation oven cycle might look like this:

• Drying - Air circulation and possibly some heat, along with introduction of fresh air through a filter, to assure that the load is fully dry.
• Load Heating - Once conditions have been achieved that indicate the load is fully dry, heat is applied to raise the chamber temperature to the required processing temperature.
• Load Exposure or Soaking - The load within the chamber must attain a minimum temperature for a minimum amount of time to assure the minimum pyrogen level reduction is achieved.
• Load Cooling - After the required exposure has been achieved, the load mass will have a substantial amount of stored heat. The removal of this heat can be achieved with filtered ventilation air or a water coil integral to the oven.

The basics are simple, but each production operation will face specific challenges related to their product, facility, and operation. Intricacies of oven air movement, load handling, filtration, sealing, process validation, and many other aspects will come into play in establishing a depryogenation process that fulfills the entire range of regulatory and organization requirements.

Share your biopharm processing challenges with knowledgeable professionals. The combination of your own process knowledge and experience with their product application expertise will yield an effective solution.

Filtration and Biological Safety Cabinets

One of several variants of biological safety cabinet
Courtesy Esco

Biological safety cabinets (BSC), of which there are several specific types, are purpose specific safety equipment enabling technicians to work with limited types of biohazards. They provide containment of the hazard while delivering a clean work space that, along with proper technique, minimizes the contamination probability of cell culture work in progress.

Arguably, the heart of the BSC is a set of filters that efficiently trap and hold particles in the recirculating and exhaust air streams. These filters keep airborne pathogens out of the work zone, but contained within the cabinet. Some manufacturers utilize HEPA filters, while others employ the higher efficiency ULPA filters.

HEPA filters are rated and tested in accordance with accepted standards to deliver efficiency levels of 99.97% when challenged with a test aerosol containing 0.3 micron diameter particles. HEPA filters are essentially depth filters, composed of a dense array of microfibers capable of trapping or preventing passage of very small particles. ULPA filters utilize a similar microfiber media that provides a performance level of 99.999% efficiency on particles of 0.1 microns. The higher efficiency and lower contained particle size for ULPA filters is considered and advantage by some.

Biological safety cabinets and their filters, regardless of type, both have very specific standard testing procedures for finished product to assure proper safety performance. Proper handling and installation of the equipment is necessary to avoid even minor invisible damage that could impact equipment performance. In place testing of newly installed or relocated biological safety cabinets is good practice, required in many cases.

Determination of the right type or class of safety cabinet for specific applications is the role of qualified safety specialists. Once the proper type of biological safety cabinet is established for a lab, choosing a specific manufacturer and model that provides the operational features and work space that best suits the user can be facilitated by consulting with a laboratory equipment specialist. The combination of user experience and laboratory process knowledge, with the product application expertise of a specialist, will yield an effective solution.

Class II Biological Safety Cabinet Ergonomic Green Considerations from Atlantic Technology Group, Inc.

Flexible Installation and Dispensing Options for Lab Water Purification Unit

Chorus modular laboratory water purification
unit, shown with dispenser integrated to bottom
Courtesy Elga LabWater

As a laboratory technician, researcher, or operator, purified water of a known and consistent quality is as essential as drinking water. The production and dispensing of purified water is a support task or operation that, while necessary, does not move the lab mission forward in a direct way. Ideally, water of the right quality will be available for dispensing on demand and lab personnel will not need to spend time checking, adjusting, or maintaining the water production and storage apparatus.

The Elga PURELAB® Chorus modular water purification units for laboratory use provide a number of features and options that enable the production and dispensing of Type 1 ultrapure water effectively and ergonomically.

• Several unit variants allow the user to select the combination of water purification technologies that best suit their laboratory needs.
• Dispensing options configure the interface between user and equipment in a manner that best suits the way technicians will dispense purified water.
• On board monitoring of component performance and water quality provide indication of when purification elements require replacement and confirm water quality and the point of delivery.

Below is a datasheet for the PURELAB® Chorus modular water purification units, showing all the available configurations and dispensing options. Share your lab water requirements with application experts, combining your own laboratory experience and knowledge with their product application expertise to develop effective solutions.

PureLab Chorus 1 Modular Lab Water Purification Unit from Atlantic Technology Group, Inc.

Atlantic Technology Group at Chesapeake Bay Chapter ISPE Conference

Tim Holden, of Avant Garde Scientific, speaks with an attendee at the
2017 ISPE Chesapeake Bay Chapter Mid-Atlantic Life Sciences Showcase

Atlantic Technology Group continued its corporate sponsorship of the ISPE Chesapeake Bay Chapter this week at the 2017 Mid-Atlantic Life Sciences Showcase held at the University of Maryland Shady Grove Campus. In addition to the educational portion of the program, there was an evening get together with a keynote speaker and various exhibits of service and equipment vendors. It was a great opportunity for participants in various facets of the industry to come together in a casual environment and share ideas and experiences, and generally have a good time among others within their professional community.

ATG showcased technical aspects of their product offerings from:

• Miele Professional - Specialized washing equipment for glass and plastic ware
• Girton - cGMP washing equipment of standard and custom design
• Elga - Point of  use water purification equipment
• Esco - Biologial safety cabinets, specialty laminar air flow stations and equipment
• BMT USA - cGMP sterilizers and ovens

On hand were David Jenkins, president of ATG, and Tim Holden from Avant Garde Scientific. Avant Garde sells and services the Atlantic Technology Group product offering in Maryland and the metro Washington, DC area.

A great organization, great event, very productive for everyone attending.