Marie Louise Laub Busk

PhD defense by Marie Louise Laub Busk

Title: Fabrication and utilisationof solid-phase microdroplet arrays for nucleic acid detection and other applications


Time and date: Wednesday, 29 May, at 13:00

Place: Building 341, Auditorium 22


Principal supervisor: Associate Professor Martin Dufva, DTU

Co supervisor: Andreas Kunding, SELMA Diagnostics

Co supervisor: Inge Høgh Dufva, Herlev Hospital



Associate Professor Anders Wolff, DTU Bioengineering

Professor Jean-Louis Viovy, PSL Research University

Senior Researcher Philipp Gruner, Novozymes


Chairperson at defence

Associate Professor Jonas Nyvold Pedersen, DTU Health Tech



Microdroplet arrays involve the compartmentalisation of biological or chemical reactions in hundreds of thousands of single compartments spatially distributed in two dimensions on a surface, for example a glass substrate. These compartments are so small that single molecules or cells can be encapsulated and interrogated. Reactions with single molecules in these droplets are detected, and precise quantification of the molecules can be achieved by counting the number of partitions eliciting a signal. This has, for example, enabled the sensitive detection of proteins by digital immunoassay, improving the limit of detection 1000-fold compared to conventional, analogue methods.

This study concerned the development of a versatile microdroplet array platform, which expands the range of applications possible on the microdroplet array. This is achieved by generating the droplets in air and capturing the biological targets directly on the array surface.

Two fabrication methods were presented and characterized, and three applications demonstrated on the arrays. Digital ELISA was applied to detect Aβ1-42 which is a biomarker for Alzheimer’s disease with a detection limit around 10 fM. Next, cell-free protein expression from single copies of DNA template was demonstrated, which enables the in-situ generation of protein or peptide arrays for numerous applications, and shows that reactions which require several washing steps and more than one incubation in droplets is possible. Lastly, preliminary results showing the detection of DNA on the droplet array was presented. 


Wed 29 May 19
13:00 - 16:00


DTU Sundhedsteknologi


Building 341, room 22