MOLECULAR AND CELLULAR IMAGING CORE FACILITY PICMI - Dep AFM


Presentation

Presentation of the Atomic Force Microscope Core Facility


Atomic Force Microscope (AFM) is a scanning probe microscopy technique that allows the study of a surface topography. To obtain it, a very sharp tip (the dimension of the radius of curvature at the apex ranges from to 2 to 20 nm) is supported by a cantilever that scans the sample. The tip is very close to the surface and “feels” attractive or repulsive forces, depending on the distance tip-surface, that are measured by the deflection of the lever. A three dimensional image of the surface is thus obtained at high resolution by detecting the interatomic force between the tip and the sample.


The Atomic Force Microscopy facility is part of the PICMI imaging core facility at the IRCAN institute (Plateforme d’Imagerie Cellulaire et Moléculaire PICMI).

 

May 2016

Managers


PICMI Scientific Responsables  :


Cedric Gaggioli ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it )    


 

Sabrina Pisano ( This e-mail address is being protected from spambots. You need JavaScript enabled to view it )     


 

PICMI Administrative Responsable  :


Nadine Fédou (nadine.fedou This e-mail address is being protected from spambots. You need JavaScript enabled to view it )

Equipment


Equipments


On site, two different AFMs are present:


- Multimode 8 (Bruker), ideal for high resolution scanning microscopy of small samples (i.e. DNA, RNA, proteins, DNA/protein complexes, nuclear membrane proteins).


This AFM can be used in different scanning mode (contact, tapping, peak force tapping) both in liquid and in air.

The system can be equipped with three different scanners as a function of the sample dimensions:

-      0.4μm x 0.4μm XY and 0.4μm Z

-      10μm x 10μm XY and 2.5μm Z

-      125μm x 125μm XY and 5μm Z


- Bioscope Catalyst (Bruker), ideal for larger and/or thicker biological sample (for instance, metaphase chromosome, interphase chromatin spreads, cells, tissues).


As the previous system, this AFM can be used in different scanning mode (contact, tapping, peak force tapping) both in air and in liquid. In the latter environment, it is possible to have a specific working temperature thanks to the temperature controller.

Available scanner ~ 150μm XY, ~ 20μm Z.


The Bioscope catalyst is coupled with an inverted optical microscope Leica Microsystems DMI 6000B (bright field, phase contrast, epifluorescence). Thanks to the optical microscope, it is possible to pinpoint the area of interest on a very large surface and bring there the AFM probe for the scanning.


Both the Multimode 8 and the Bioscope catalyst can perform topographic and/or mechanical properties characterization of the sample.

Some Samples


Some Samples



              a)         b)    

              c)


a) plasmidic DNA

b) nucleosomal array reconstituted in vitro

c) different multimeric complexes of the telomeric TRF2 protein:

each dimer wraps 90 bp of DNA, producing an apparent

shortening of DNA if compared with the length of the naked DNA





                                 

a)                                             b)                               c)

a) Example of superimposition of optical and AFM topographic images of a fibroblast cell

b) and c) Quantitative mechanical properties maps, modulus and deformation

respectively obtained simultaneously to the topographic image





                  

a)                                                     b)                                          c)

a) Optical image of the area of a murine skin slice scanned by AFM

b) Mechanical map of the same area

c) 3D topographical image of the area of interest  

AFM Charter

 


Please download the general AFM charter of use