Chitozen

The 1st functionalized microscope coverslip to image live bacterial cells & study their growth and behavior. 

Overview

Chitozen is a chitosan-coated coverslip compatible with 6-channel sticky slides.

It is very helpful if you want to 

  • image bacteria both still and alive under the microscope
  • Maintain bacteria in a same focal plane for imaging while preserving their physiology 
  • Renew culture medium and change the growth condition (e.g. antibiotics, chemicals, inhibitors) during the experiment and directly observe, in real-time, the bacteria new comportment under the microscope.

A technology designed by   ​m ​ Mignot , Olivier Theodoly , Amandine Desorme , Guillaume Sudre and Laurent David .
Published in mBio / ScienceAdvances

E. coli but non only

Chitozen is efficient on the following bacteria: 

  • E. coli
  • Vibrio cholerae
  • Myxococcus xanthus
  • Mycobacterium smegmatis
  • Bacillus subtilis
  • Pseudomonas aeruginosa
  • Pseudomonas fluorescens
  • Salmonella

We update this list regularly according to feedback provided by researchers who use Chitozen.

Videos & images

 
  

E. coli monolayers on Chitosan
© 2019 Tréguier et al. This content is distributed under the terms of the Creative Commons Attribution 4.0 International license.

 
 

Visualization of Pal mCherry at septum in E. coli (W3110 Pal mCherry), by 3D SIM microscopy, in M9 medium and using Chitozen.
Credit : Amandine Desorme - LCB - CNRS - 2021


Features

High adherence

Maintains bacteria in a similar focal plane for imaging

Preserves cell physiology

The chitosan coating is free from bacterio-static effects and does not affect bacteria geometry

Perfusable

Change the medium or add compounds throughout experiment to assess real-time changes in bacterial behavior


Easy-to-use

Suitable as an easy starting tool to get trained on bacterial imaging

Time-saving

Test up to 6 parallel conditions on one slide

 

Protocol

 
 
 
 
 
 
Chitozen: how to use it, a video protocol from assembling the elements to imaging your favorite bacteria.

Simplified protocol


ASSEMBLE COVERSLIP & STICKY-SLIDE


LOAD 1 SAMPLE PER CHANNEL

CENTRIFUGE OR LEAVE BACTERIA TO SETTLE


IMAGE

Going further: perfusing the system with flow

Odoo • A picture with a caption
Chitozen coverslips allow bacterial cells to be immobilized even under a flow.

Feedback from users

Chitozen has been successfully tested by users on the following bacteria: 
 E. coli
 Mycobacterium smegmatis
 Bacillus subtilis
 Pseudomonas fluorescens
> Salmonella.

These results supplement those obtained by Tâm Mignot and al. with:
 E. coli
 Vibrio cholerae
 Myxococcus xanthus
 Pseudomonas aeruginosa

Feedback by Emily Helgesen

Oslo University Hospital, 2022

Live cell imaging of E. coli in response to drug addition on Chitozen slides

AB1157 E. coli expressing DNA marker HU-mCherry were imaged at 37oC with perfusion of ½ LB at a flow rate of 2 ml/min. Drug X was added at time point 35 minutes and removed at time point 60 minutes. Credit: Emily Helgesen - 2022

Live imaging of E. coli expressing a protein associated with DNA replication on Chitozen slides


AB1157 E. coli cells expressing SeqA-YFP (pseudo colored green), a protein associated with DNA replication, were imaged at 37oC over 60 minutes without perfusion of medium. 
Credit: Emily Helgesen – 2022

Feedback by Bianca Sclavi

Sorbonne University, 2021

Effects of cell division inhibitor cephalexin on E. coli growth cultured on Chitozen slides

 
 
E. coli BW25113 cells were imaged at 37°C with perfusion of M9 medium at a flow rate of 0.05 mL/min. 
Credit: Bianca Sclavi - 2021



Feedback by Itzhak Fishov

Ben-Gurion University of the Negev, 2022

E. coli spheroblasts bound to Chitozen

E. coli MG1655 with chromosomally encoded HU-eGFP under the native promoter were imaged with perfusion at a flow rate of 0.05 mL/min. Credit: Itzhak Fishov – 2022

Feedback by Maxence Vincent

University of Oxford, Jan. 2022

Tracking of DNA repair proteins in live cells of Escherichia coli   

"Cells expressing HaloTagged DNA repair proteins were loaded onto the chitosan-coated coverslip and imaged with TIRF microscopy. The Chitozen technology enables tracking single-molecules while changing environmental conditions (e.g: M9 or M9 + mutagen). Computation of the diffusion coefficients provides insights into how proteins change their mobility upon DNA damage".

Maxence Vincent • University of Oxford, Jan. 2022

Credit: Maxence Vincent - 2022
Odoo • A picture with a caption

Feedback by Jerome Rech

LMGM-CBI-CNRS, Toulouse, 2022

Time-lapse images of E. coli growing: Localization of F-plasmid

Odoo • Image and Text Cells are observed in phase contrast (top), in the blue and yellow channels for fluorescence microcopy to observe phase contrast, nucleoid (DAPI) or F-plasmid (mVenus tag), respectively.
Overlays of phase contrast and blue or yellow channel are shown on middle or bottom panels, respectively.
Cells were grown at 30°C in supplemented M9 minimal media containing Cystein and DAPI under continuous flow. Scale bar (2 µm). Credit: Jerome Rech - 2022

Technical information

Compatible with: phase-contrast, epifluorescence, confocal, super-resolution microscopy

Kit description

5 standard (25 x 75 mm) chitosan-coated coverslips with 5 sticky slides.

Each Chitozen coverslip allows up to 6 assays using bottomless 6-channel sticky slides. 


Lifetime: up to 12-month storage at room temperature, shielded from direct sunlight.

 Resources:
FAQ
Technical Datasheet
Safety Datasheet

Story

" We wanted to understand how our bacteria, Myxococcus xanthus, moves on a surface. So we tried to design a smart microscopy system to observe it. But there was a problem: the Myxococcus cells were not adhering to our glass slides. When we read a paper on how people use chitosan to get their bacteria better move on plates, we got an idea: maybe we could coat our glass slides with some chitosan?
Odoo • Image and Text
We tested it. And it worked! We then implemented our prototype with a microfluidics system to test the real time response of our bacteria to antibiotics. Now we’re thrilled to share it with the community of research! We hope that people working on bacteria will appreciate to use Chitozen because it is a very easy system to run that combines microfluidics and high-end microscopy. We are looking forward to getting feedback of use: it will mean that we have developed a device useful to the community and that is always a deep satisfaction! " 

Tâm Mignot, Olivier Théodoly, Amandine Desorme, Guillaume Sudre, Laurent David ​ 

Esther Graudens
New projects at Idylle
" We really loved the way all the team, whether in Marseille or in Lyon, was deeply concerned by the tiniest detail and willing to prepare the best ever product for the community. So if you want to know more about how we co-designed and produced Chitozen starting with chitosan, then catch an eye on   The story of the Chitozen Tech Transfer
And if you are interested in seeing what you can do with chitosan-coated coverslips, you can have a look at this study published by the team of developers in 2019. They've managed to use chitosan-coated coverslips to promote the growth of cells without any deleterious effect on their physiology, allowing them to measure the antibiotic susceptibility of a diversity of clinical strains with an excellent accuracy in a very short period of time. Read all about it here: mBio, 2019"

Contact us about your challenges to image your bacteria

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