Second speaker is @teunhuijben.bsky.social from @loicaroyer.bsky.social group at @czbiohub.bsky.social #CBIAS2025
Tracking is hard because segmentation is hard, especially in whole zebra fish embryos: Ultrack can help github.com/royerlab/ult...

Hi Eric, could you add me to the Science 🧪 feed? I am employed at the Chan Zuckerberg Biohub in San Francisco working at the interface of developmental biology, microscopy, and machine learning.

Google Scholar: scholar.google.com/citations?us...

Orcid: orcid.org/0000-0002-89...

Congrats on the paper! Also, it’s time to bring Sjoerd Stallinga over to the BlueSky-verse ;)

10/ Thanks to all co-authors: Sarojini Mahajan, Masih Fahim, Peter Zijlstra, Rodolphe Marie and Kim I. Mortensen🙌. And of course our #Horizon2020 #MSCActions SuperCol ITN network! 🥳

9/ In addition to the metal nanoparticles (gold 🟠), Masih Fahim’s work showed that the same holds for dielectric (polystyrene ⚪️) particles, allowing us to reconstruct the distribution of single DNA molecules on the nanoparticle surface 🧬

8/ In this way, we can map out the full surface. We show that the surface functionalization is patchy and heterogeneous between particles. This will allow studying the surface functionalization at the single-particle level to design and produce the nanoparticles of the future.

7/ Fitting the experimental images with our new analytical PSF model, we obtain the coordinates of the emitters relative to the nanoparticle surface. Allowing us to map the position of the DNA strands that engaged in DNA-PAINT, with <5nm precision!

6/ To showcase the fitting approach, we perform DNA-PAINT on DNA-coated 100nm gold nanoparticles, resulting in a zoo of exotic PSFs!

5/ We developed the first-ever analytical PSF model for a fluorophore near a spherical nanoparticle, of any size, material, and composition. Our model is 4 orders of magnitude faster than numerical calculations, allowing us to use it directly to fit experimental data.

4/ The PSF doesn’t always deform in the same way, but the PSF shape depends on the fluorophore’s position relative to the nanoparticle. This means that the PSF shape encodes information about the fluorophore’s position, which we can use to our advantage during localization.

3/ A single (freely rotating) fluorophore creates a symmetric PSF, which we conventionally fit with a 2D Gaussian. However, the presence of a nanoparticle deforms the PSF, resulting in significant biases when simply fitted with a Gaussian.

2/ Nanoparticles are important for biosensing, drug delivery, and cancer therapy. The functionality of the nanoparticle crucially depends on the distribution and number of functional groups on their surface, which can ideally be studied with localization microscopy🔬