By: Mary N. Wessling, Ph.D. ELS

List Labs Genesis Lyophilizer

Genesis Lyophilizer


What is Lyophilization?

Protecting the activity of enzyme products and the viability of bacterial cultures that are used in scientific experimentation is an area where List Biological Laboratories is a leader. Lyophilization has been the most extensively used technique for maintaining the integrity of biopharmaceuticals. Lyophilization (otherwise known as freeze drying) is a sublimation process: the liquids in the product go from a frozen state to a gaseous state without going through a liquid phase, leaving behind dry solids.


The Steps of Lyophilization

The lyophilization cycle proceeds through three steps:

  1. freezing, in which the product is brought to a temperature below its freezing point at a rate that produces water crystals of ideal size;
  2. primary drying, during which the crystals undergo sublimation under vacuum;
  3. secondary drying, which removes residual water vapor after the primary drying. Finally, the lyophilized product may be sealed in an inert gas atmosphere.1


Why Lyophilization is Important

Lyophilized formulations of biopharmaceuticals must be approached based on the specific vulnerability of the original product. List Labs is very experienced in producing lyophilized products; most of our stock products and many of the products produced through our GMP Contract Manufacturing services are lyophilized. To ensure activity and viability, List Labs evaluates the use of various sugars, proteins, small molecules, polymers, and salts in candidate formulations. Also, the products can be aliquoted into vials and lyophilized, which makes for increased efficiency of use and preserves the integrity of the product when used in experimental studies over some time. The demands for quality and safety of biological products, such as vaccines, are very stringent;2 the FDA document regarding lyophilization of parenterals provides a useful overview of the lyophilization process from a regulatory point of view. List Labs’ lyophilized products have been used in a wide range of experimental procedures for more than thirty years.


  1. Chang BS, Reilly M, Chang H. Lyophilized Biologics. In: Varshney D, Singh M, eds. Lyophilized Biologics and Vaccines. New York: Springer; 2015:93-119.
  2. Bloom BR, Lambert P-H, eds. The Vaccine Book. 2 ed. Amsterdam, Boston: Elsevier Academic Press; 2016:90-92. PMCID: PMC3323310




Since 1978, List Labs has been known as a manufacturer of fine research reagents.  Located in Silicon Valley, our company is woman-owned and managed.  We enjoy long-standing relationships with many researchers who have used our products for decades, bringing the continuity of List’s products along with them as they move up to new career opportunities.

Full Range of Contract Manufacturing Services

In addition to our catalog products, we offer a full complement of professional services, including:  GMP Contract Manufacturing, Production of Live Biotherapeutics, Contract Research, Formulation/Lyophilization and Navigating both Toxin Compliance, and Regulatory Requirements.  Our manufacturing  and biocontainment experience, and our well-established record of working with partners to successfully bring products to market makes us a great service provider to companies of all sizes.

Full cGMP Facility

List Labs offers a full cGMP facility, and labs designed to meet the most exacting requirements including biocontainment. See our equipment list here. Our scientists are experts at working with pharma, start ups, government and entrepreneurs to further their research, to produce API , and to perform testing.  We extend our clients’ capabilities!

Start Your Partnership with List Labs Today!

If you have a project and you’d like to work with a partner who can work independently or as a member of your team, has their own state of the art lab suite, understands key requirements and navigating regulations implicit in toxin production, then contact us to discuss your needs.

List Labs has a compelling history of successful partnerships, ask us to tell you how we’ve helped bring major products to market and why we are a critical link to the scientific success of the work we do.  Check out Citations where our products have been used in research.

We will be attending BIO2014 in San Diego June 23-26 where we will be meeting with companies who have an interest in our wide range of Professional Services.  We are also happy to arrange a meeting and tour at our California office. Just email us.