Supplies of Zell Kontakt products

Zell Kontakt is a German company making fantastic glass bottom dishes and plate. Check out why the LCI facility likes their products (absolutely no commercial interests!).

Great products but crap communication skills! Either their website is down or they do not answer the phone and emails and anyway if they do, make sure you have a German colleague around because no one speaks English.

Now we have found a way around the problem: MoBiTec sells Zell Kontakt products. 🙂

How to precisely measure the volume of a cell?

Measuring the volume of a cell is often done by labelling the cell membrane or its cytoplasm. Analysing large flat cells this way is easy but it is much harder for tiny cells like blood cells, yeast or bacteria.

Another way to measure volumes is to use a negative stain, i.e. where the medium is made fluorescent with a dye that does not go into the cell. The cell appears as a black hole in fluorescent images and unlike lipid-based membrane labelling, borders are even and easy to segment.

While many dyes can be used for live cells, one must choose large dyes when negatively imaging cells that have been fixed and permeabilized.

This paper and this one use high molecular weight (2000 KDa) Dextran to achieve these results and measure the size of bacteria.

This recent paper optimizes the technique.

 

Free genetic and image analysis tools

Here are a few image analysis tools (constructs for FRET, software…) that might be useful to you.

  • Construct for fluorescence biosensors and optogenetic tools
  • Free Image analysis software

http://www.hahnlab.com/tools/index.html

  • Free Image analysis software

https://www.utsouthwestern.edu/labs/danuser/software/

  • Free Image analysis software

http://cismm.web.unc.edu/

Party time at the LCI! :D

On the 10th of October, the Live Cell Imaging facility will have an open house and a little party to celebrate loads of great stuff:

  • The LCI turned 10 years old this year! 😊
  • We got a wonderful light sheet system earlier this year. It is high time to give it a name and splash it with a bit of champagne!
  • Gisele Miranda from Scilife/BII has joined the LCI team to help our users with image analysis
  • We got a great server/analysis capacity set up by the KI IT department

Wow! What a year! 😃

Please come and celebrate with us! If you do not know what our microscopy facility has to offer, it is time to be curious and pay us a visit.

  • Open house: drop in between 9:00-11:00
  • Baptising of the light sheet system and celebration of Gisele and our shiny new server: at 11:00

All this will happen on the 10th of October (next Thursday) at the LCI facility, on the 7th floor of Neo at KI Flemingsberg. Here you can see how to find us.

Please help us spread the news! 😊

Deep red fluorescent proteins

The microscopy field is moving away from blue dyes. This is because red light, used to excited far red and deep red fluorophores, is less damaging to live cells than near UV light which is used to excite blue fluorophores.

On top of that, red light penetrates deeper into thick samples.

So as the trend in microscopy is to move to thicker samples and use more live samples, far red and deep red fluorophores are becoming more attractive.

Here is an article describing 3 new fluorescent protein in the far red to deep red range. One can excite them with 640 nm or a 685 nm lasers or LEDs.

EMBL microscopy event in Göteborg

Nice speaker line up at this 1 day event on the 18th of october.

Organized by Astra Zeneca, EMBL and several Swedish universities, this is a good mingling event for microscopists! 😀

Crest V3 spinning disk confocal demo

Tomorrow (17 sept) we will enjoy a seminar and a live demo about the Crest V3 spinning disk confocal which is being set up at our facility as I write! 😀

Very cool confocal!

  • enormous field of view (32 mm diameter)
  • fully confocal
  • can image at 100 frames per sec
  • spits out Nyquist resolution with the 60x objective!

You can come to the seminar (at 10 in the Gene seminar room at the LCI facility) or listen to it remotely (see here how to follow the LCI webinars).

You can even book a private demo to image your own samples.

Matching the refraction index of live samples

To image a thick sample, it is crucial to match the refraction index of the sample with that of the immersion medium between the sample and the objective. Typically, life samples are in an aqueous solution like culture medium which has a refraction index of 1.33. Unfortunately organoids often have a higher refraction index closer to 1.44 therefore as one images deeper into the organoids, light scatters due to the refraction index mismatch and the images become blurry.

This paper presents a product that has a high RI and is compatible with cell culture. Good to keep in mind for those who image organoids over time.

How to identify cells and nuclei in an image?

NucleAlzer is a great new deep learning tool to identify roundish objects like nuclei and cells in fluorescent or bright field images.

To test if the tool works for you before you download it, you can simply upload one of your images and check the result. Easy! 😀

Call4Help: fast-track help with your image analysis project!

BII (BioImage Informatics, the great image analysis at SciLife Uppsala) and the LCI facility will run a new Call4Help on the 4th of September.

Anyone who is stuck with image analysis and wishes for quick help to build a pipeline should apply. You don’t have to acquire the images at the LCI. Anyone can apply.

How does it work? You first upload your images and a little explanation text. A few days later, we all meet virtually in a Zoom chatroom for a quick (30 min-1 h) online session. You get comments, suggestions and help with building a Fiji or CellProfiler analysis pipeline tailor-made for your images.

If you are interested, click on the link below to apply:

BioImage Informatics