iiinova — where your digital self keeps evolving

Reposted by Julia Lazzari-Dean

Alfred Millett-Sikking @amsikking.bsky.social · 20/07/2026

Ultrafast 3D imaging just got faster! Introducing: "Instant dual-view Snouty (iDV-Snouty) light-sheet microscopy" -> Double the data rate of a Snouty microscope by adding a 2nd view! Use the extra view for a variety of imaging modes! Article here: amsikking.github.io/idv-snouty_l...

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Reposted by Julia Lazzari-Dean

Andrew G. York @andrewgyork.bsky.social · 29/04/2026

Meet MagLuc: a magnetically-controlled luminescent protein. This is a foundational tool for remote control of biological processes, also known as "magnetogenetics". Can you tell when the magnetic field turns on and off? From @mariaingaramo.bsky.social and the team at @nonfictionlabs.bsky.social

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 13/05/2026

Neat! Yeah I'd imagine that coupled to actin vs. free would lead to a pretty big difference in tumbling rate

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

I'm pretty excited about the idea of engineering fluorescent proteins (or other tags) to be more optimized for triggered triplet generation...right now, we're just using "off the shelf" mStayGold, so it would be cool to see how much more signal we could get with more targeted screening

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

I was really concerned about brightness as I was developing the method, since triplets are not very abundant relative to singlets....& brightness is definitely a limiting factor, BUT we have enough signal to do single-trial recordings in cells with abundant targets

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

Yes, exactly! We are reading out the fraction bound, not kon or koff of the binding. in the current prototype, we select a ROI within the cell but don't take a full image all at once because of laser power limitations. That's not fundamental, though - just something on our test system

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

Thanks Tamas! With an IDR-heavy protein, you'd have segmental motion, so the tumbling wouldn't reflect the mass of the overall protein TTM would tell you local mobility of the protein near the tag, which might still be informative re: interactions, depending on the target & tag location

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

One thing to think about with large complexes would be segmental motion in the complex. In that case, the motion might be more sensitive to binding in the local environment of the tag versus the overall size of the complex (i.e. tag position on the complex could affect your sensitivity)

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

Great question! I've been able to see something like a ~10% change in a 100 kDa protein, so my guess is that the limit of detection would be on that order. Is the complex associated with the cytoskeleton? If so, the tumbling would be a mix of how anchored it is and its size

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

If you’re interested in a more theoretical treatment of this topic, also check out the simulation paper we shared in 2023: andrewgyork.github.io/tumbling_is_...

andrewgyork.github.io

Tumbling is general

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

Further reading: check out Ilaria Testa’s lab’s work from 2023, using reversible switchable fluorescent proteins (rsFPs) to extend anisotropy to large protein complexes. Manipulating rsFPs instead of triplets gives more total signal (but less in the sub-us time range). doi.org/10.1038/s415...

doi.org

Extending fluorescence anisotropy to large complexes using reversibly switchable proteins - Nature Biotechnology

STARSS measures rotational dynamics of large molecules and their complexes.

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

Also a huge thanks to Calico Life Sciences LLC for making science like this possible

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

Big thanks to @andrewgyork.bsky.social & @mariaingaramo.bsky.social for inventing this technique with me, @amsikking.bsky.social for instrumentation, Magdalena Preciado-Lopez for application areas, Prashant Rao for FSEC, Aaron Nile, Zena Jensvold & Hannah Baddock for driving the E6 application

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

I’m very excited about this technology, but it’s also far from finished! There’s lots of room to iterate: fluorescent tags with better triplet yield, better rigid tagging strategies, and more refined instrumentation for triplet tumbling imaging. It’s more than we can do on our own!

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

We can detect some pretty small mass changes: on the order of 10%! Here, we visualize the binding of the viral protein E6 to the E3 ligase E6AP. This protein-protein interaction contributes to HPV-induced oncogenesis: being able to see this interaction is key to developing ways to disrupt it.

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

One of the cool things about triplet tumbling microscopy is that it isn’t restricted to one-to-one heterodimerization interactions. We demonstrated that we can capture the differences in the p53 homo-oligomerization state (a mixture of monomers, dimers, and tetramers) using this approach.

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

When we translate this system into cells, we can see FRB and FKBP bind in real time when we add the rapamycin dimerizer. 2 things to highlight: -we have information about the FRB partner size even though only the FKBP part is tagged -this data was taken at 3 Hz & is single trial, unaveraged

A graph of time course data of cells treated with rapamycin dimerizer, causing protein heterodimerization. The untreated cells show no change, whereas treated cells show a tumbling change that depends on the mass change.

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

We can easily see a 41 kDa protein bind a 15 kDa protein in our recombinant system. We can also distinguish binding partners of different sizes. We demonstrated this by tagging the protein FKBP & adding a drug (rapamycin) that induces binding to FRB. Note that this isn’t FRET: only FKBP is tagged.

Results of fitting triplet tumbling data, demonstrating that we can extract size of the protein complex from tumbling rate

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

To measure orientations over microseconds, we generate triplets with a pulse of visible light and then “trigger” them with infrared light. We illuminated a ~4 um (FWHM) spot because of limited laser power, but this design extends to larger fields of view…most optimally in a lightsheet geometry

A schematic of the illumination sequence, with a pulse of 488 nm light first used to generate triplets (and singlets), followed by a pulse of infrared light to measure orientation

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

2 years ago, we shared that this was possible based on simulations and a proof-of-principle with beads on a hacked commercial instrument. Here, we’ve taken it all the way: we built a custom microscope to implement this well, and we show it works with proteins in living cells.

An optical diagram of the instrument developed for triplet tumbling microscopy

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

You might be thinking: this sounds like fluorescence anisotropy. Yes, except we solved anisotropy’s size limitations! Fluorescence anisotropy doesn’t work for particles >50 kDa: they tumble too slowly. To measure proteins of all sizes, we use infrared-triggerable, delayed fluorescence from triplets

A timeline showing how tumbling rate corresponds with particle size

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

How does it work? We measure protein size from how fast it “tumbles." All proteins tumble, and bigger (or bound) proteins tumble more slowly than smaller ones. We watch how fast the orientations scramble after a pulse of polarized light to measure tumbling. Animation @drlachie.bsky.social

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 12/05/2026

We invented “triplet tumbling microscopy” (TTM) to track protein-protein interactions in living cells! Tag your protein with GFP and see it interact with *untagged* binding partners www.biorxiv.org/content/10.6...

A cartoon overview of triplet tumbling microscopy, comparing data from bound and unbound samples.

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 05/05/2026

Early projects will involve laser capture microdissection, proximity biotinylation, and/or fluorescent biosensors. We’re looking for someone with the flexibility to work on diverse projects: this role will evolve, and we’d like to work with someone excited to evolve with it.

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 05/05/2026

Our ideal candidate is… -deeply expert in fluorescence microscopy: think >50% of your work effort over years -a “flexible hybrid:” engages with the technical aspects of microscopy (instrumentation, sample preparation, analysis) and downstream applications -early career

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 05/05/2026

We’re hiring a scientist to work on microscopy at Calico! If you’re excited about developing and applying cutting edge microscopy to a variety of biological questions, we’d love to hear from you. Find more information and apply here: www.calicolabs.com/careers/?gh_...

calicolabs.com

Careers - Calico

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 09/03/2026

Hi microscopy folks! I'm looking for your advice 💡 We're shopping for cyclic immunofluorescence instruments to increase throughput and multiplex-ability of tissue IF. Have you worked with cyclic IF platforms (Comet, CellScape, Cell DIVE)? Thoughts? Pain points? Alternatives to consider? Thanks!

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 05/01/2026

I've spent many afternoons crouched over a microscope with a pipette, waiting for the exact right moment to add my perturbation (& not breathing so I don't bump anything). Now I can just program it in and have a more relaxing experiment :)

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 18/12/2025

The official deadline is February 1, 2026, but we'll start reading applications as they come in. To be eligible, you must be currently enrolled in a PhD program at a US university (sorry, awesome international microscopists).

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 18/12/2025

I'm excited to be hiring an intern to develop new fluorescence-based assays for alpha synuclein aggregation at Calico during summer 2026 😃 🔬 If you're a current PhD student who loves microscopy, unnatural amino acids, and/or synuclein biophysics, please apply! www.calicolabs.com/careers/?gh_...

calicolabs.com

Careers - Calico

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 05/12/2023

If you want to read more, please check out the full paper here: andrewgyork.github.io/tumbling_is_... We think it will work with most fluorescent proteins and (relatively) minimal modification of existing instruments

andrewgyork.github.io

Tumbling is general

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 05/12/2023

Want to measure protein-protein interactions? We recently did some dreaming about how you can do this with a single fluorescent tag using molecular "tumbling." We simulated how you'd do this on a lightsheet, a flow cytometer, or a cheap handheld device. We even took prelim data on a commercial rig:

Data from an unmodified commercial confocal instrument that we jerry-rigged into taking tumbling measurements. A proof of principle & far from what you could do with a custom rig!

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Reposted by Julia Lazzari-Dean

DrLachie @drlachie.bsky.social · 30/10/2023

I no longer have the follower count nor the algorithm to help promote stuff, but @jlazzaridean.bsky.social and Andy York reached out to me a while ago to do an animation explaining a way to measure moluecular "tumbling" and I think it worked out pretty well! andrewgyork.github.io/tumbling_is_...

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Julia Lazzari-Dean @jlazzaridean.bsky.social · 24/10/2023

Hi bluesky! Excited to share some new work in voltage sensing I was a part of in my past life in the Evan Miller lab at Berkeley: a versatile dye for both fast voltage imaging and lifetime-based quantification Introducing CRhOMe: www.biorxiv.org/content/10.1...

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