Nucleation, the first step in any first-order phase transition, is one of the most secretive processes in chemistry, physics, materials science, biophysics and biotechnology; predictions of nucleation rates and yields often deviate from reality by several orders of magnitude. It is widely accepted that the nucleation of protein crystals and ordered aggregates follow a two-step mechanism: in a first step, clusters of dense protein liquid are formed, within which, in the second step, ordered nuclei form [1, 2]. Because it is the first phase of the crystallization/aggregation process, nucleation controls numerous properties of the emerging phase. Nucleation also underlies the formation of fibrils and aggregates observed in diseases such as Alzheimer and cataract.
Both theory [3] and experiments [4] have indicated that shear flow during crystallization will affect the nucleation rate, the size of the emerging phase and even polymorphism. To further investigate this influence, we have developed a new setup that will enable us to create a controlled constant shear flow profile in a solution. The equipment consists of a stationary glass plate; a fused silica wafer with microfluidics channels connected to a rotation stage and Peltier elements for temperature control. To monitor the crystallization an inverted microscope setup is used with the option of adding filters in the optical pathway, enabling fluorescent microscopy.
The wafer will rotate with respect to the stationary glass plate, this will result in a constant shear flow in the channels. Simulation performed with COMSOL Multiphysics 5.0 [5] confirm these assumptions and characterize the deviations from the ideal profile at the walls and inlets. The nucleation and growth can be controlled by changing temperature, as such the nucleation phase can be separated from the growth phase, enabling the study of the effect of shear flow during both phases.
Original languageEnglish
Title of host publication23rd National Symposium On Applied Biological Sciences - Abstract book
Place of PublicationGhent, Belgium
PublisherGhent University
Pages3-3
Number of pages1
Volume83
ISBN (Print)ISSN 1379-1176
StatePublished - 8 Feb 2018
EventNational Symposium for Applied Biological Sciences - Vrije Universiteit Brussel, Brussel, Belgium
Duration: 8 Feb 20188 Feb 2018
https://www.biw.kuleuven.be/nsabs2017

Conference

ConferenceNational Symposium for Applied Biological Sciences
Abbreviated titleNSABS
CountryBelgium
CityBrussel
Period8/02/188/02/18
Internet address

    Research areas

  • controlled shear flow, Nucleation

ID: 36652707