Antifreeze proteins (AFPs) exist in various overwintering plants, inhibiting ice growth and recrystallization between cells. AFPs combine with ice to prevent water molecules from adhering to continuously growing ice crystals, resulting in the aqueous solution's non-equilibrium freezing point being lower than its melting point. This phenomenon is called thermal hysteresis. All of the antifreeze proteins identified to date have thermal hysteresis, and assay of the thermal hysteresis is an important step in evaluating antifreeze activity. 

CD BioSciences provides thermal hysteresis assaying services for antifreeze proteins. Our methods mainly include microscope observation, micro osmometer, differential scanning calorimetry (DSC), and sonocrystallization. By assaying the thermal hysteresis, customers can understand the activity of antifreeze proteins. 

Service Content

Microscopic Observation Service

We observe the freezing point and melting point of ice nuclei under a microscope, and the decrease between the two indicates thermal hysteresis. However, using this method only applies to individual ice nuclei.

Micro Osmometer Service

We calculate the thermal hysteresis through empirical formulas based on the changes in osmotic pressure before and after the crystallization of the system. This method is currently commonly used. Customers only need to provide a small amount of samples to obtain accurate and reproducible assay results.

Differential Scanning Calorimetry (DSC) Service

We provide a DSC method to detect changes in heat absorption and release during the crystallization process to obtain thermal hysteresis. This method provides more accurate and objective results, and can also accurately determine the ice crystal content of the system.

Sonocrystallization Service

We measure thermal hysteresis by initiating the crystallization process with ultrasound. This method can detect the complete heating, melting, cooling, and freezing processes in one measurement. The results displayed are highly reproducible.

Notification for Sample Preparation and Handling

Detergent must not be present in the solution.

Salt concentration less than 50mM.

Add sufficient dry ice during transportation.

CD BioSciences is a biotechnology company focused on plant protein research, providing a variety of related services and products for environmental and energy solutions. If you are interested in our services, please contact us for more details. 

For research use only, not for clinical use.