Building a vertical magnetic tweezers design difficulty

Hello! My name is Riley and I am a physics REU intern at the Catholic University of America. I work in a biophysics lab currently running experiments on DNA strands using magnetic tweezers. We are currently using a horizontal magnetic tweezer setup, and wish to design a vertical magnetic tweezer setup which we will be able to use in the lab. My summer project is to design this vertical setup, including a parts list of everything which will need to be purchased and explanations for why each part is needed in the experiment. I have made a rough draft of the list of parts I will need below. I am writing this to ask for any guidance anyone might have on a few items on this list. I understand that we will need to utilize a high fps camera- preferably CMOS, and a bright light source, however I am unsure of how to tell if these two items will work together in my experiment. A.K.A. I am unsure of what equations to use to determine if the light source emits enough photos for the camera rate. As well as this, I am unsure of how to tell which cameras will be able to connect to a GPU and CPU tracking system. I am also unsure of how to tell if the field of view of the camera paired with the magnification of the objective lens, and any other lens added to the system- will work in the system. I also do not understand how the pixel resolution factors into any of this. I also do not know how to attach the motors for the magnets to the magnet holder so that they will move it. I do not know how to find parts which will connect to the microscope body either. Iā€™m also wondering how to find a micromanipulator which will hold a Tygon tube and insert it into the flow cell from above. All in all, I am widely inexperienced in making an apparatus like this and any guidance would be helpful. Thank you.


  • A high frame rate (over 500fps) cmos camera, which can be connected to a GPU and CPU tracking system
  • A light source, either LED or SLD which will emit enough photons to be captured at the high frame rate
  • A microscope body to mount the components on (most likely over 450mm)
  • Breadboard appartuses for holding the flow cell, and possibly holding the light source
  • micromanipulator translation and rotary motors for movement of the magnets
  • An objective lens with a high magnification (40x or above) and high NA (over 0.8)
  • Linear translation for objective lens
  • Micromanipulator motor for the insertion of a tube into the flow cell
  • Optics equipment including but not limited to a condenser or collimator lens between the flow cell and the light source, and a tube lens or mirror between the camera and the objective

Not from thor labs:

  • GPU tracking system
  • Magnet holder (custom designed)
1 Like

Hi Riley,
we are also planning to build the same setup if you have the list, can you please share it? Thanks a lot