Lyophilization is a dehydration process where water or a solvent is removed from a material by sublimation to create a stable preparation. The material is first frozen to solidify the liquid and then subjected to reduced pressure. As the temperature is increased, the frozen water or solvent undergoes sublimation, transitioning to vapor without first passing through the liquid phase. This removes the frozen molecules from the material. A drying phase removes any remaining water or solvent.

Lyophilized beads start as a liquid formulation that typically consists of a buffer, excipient(s) to provide structure and mechanical strength, and the critical reagent, antibody, conjugate, magnetic particle, etc., at a defined concentration. The formulation is dispensed into liquid nitrogen in precise, uniform droplets, frozen, collected, and then lyophilized. This process ensures that the chemical or biological activity of the reagent is preserved.

These lyo-beads can then be used in medical devices and molecular and point-of-care diagnostics to preserve, maintain the integrity of, and deliver critical reagents. Addition of a solvent such as water restores the reagent/molecule to its original state.

Packaging and delivering critical reagents and other molecules in lyophilized beads offer many advantages for medical devices and point-of-care diagnostics:

• Enhanced stability of sensitive chemicals and biologicals and a longer shelf life
• Simplified storage, transportation, and handling
• Rapid rehydration and reconstitution while maintaining structural integrity and functionality of the critical reagent/molecule
• Improved solubility compared to non-lyophilized materials
• Eliminates the need for aliquoting and freezing following reconstitution
• Reduced risk of contamination due to the elimination of liquid from the formulation and eliminates or reduces the need for anti-microbial agents
• Enables increased flexibility in package design for the assay or medical device
• Increased cost effectiveness due to ambient temperature storage and shipping methods

Lyophilized swabs are typically used for quality control of lateral flow assays that detect the presence of infectious pathogens such as those causing COVID-19, seasonal flu, and tuberculosis. Protein, DNA, RNA, or inactivated control strains can be lyophilized onto a swab to mimic processing of a patient sample and are intended for use in healthcare settings to test the functionality of every component of the assay.