Model 2550

Cryo Transfer Tomography Holder
  • Suits both tomography and single particle cryo-EM 
  • Works for other soft materials that may require cooling when imaging
  • User friendly for specimen loading
  • Unique mechanism for specimen unloading 
  • Extended field of view at high tilt up to 80° (in TEMs with cryo pole pieces)
  • Resolution to 0.18 nm 
  • Low drift rate of 1.5 nm/minute
  • Operating temperature below -175 °C
HSV imaged using the Model 2550
Herpes simplex virus type 1 (HSV-1) KOS C-capsid. The capsids are icosahedral, 1250 Å in diameter and the sample includes DNA-filled C-capsids, as well as empty A-capsids and B-capsids that retain some component of the scaffold structure used in their assembly. The background includes strands of double-stranded DNA (dsDNA) that has been lost from some capsids. Taken by FEI TF20 TEM (magnification 50000x at 200 keV, electron dose of ~20-25 e-/Å2) using Fischione Instruments’ Model 2550 Cryo Transfer Tomography Holder at -178 °C. Sample prepared using FEI Vitrobot Mk III on Quantifoil R2/1 grid. Image courtesy of Alexander Makhov, Jamie Huffman, Fred Homa, and James Conway, University of Pittsburgh School of Medicine.

Simple specimen loading and transfer

The innovative design of the specimen tip makes loading and unloading of the specimen easy. To load a specimen, the holder is inserted into the cryo work station or the TEM to cool down. The holder dewar and the cryo work station are both filled with liquid nitrogen. The modular design of the cryo work station’s grid box allows you to reposition the reservoirs to enhance ease-of-use for both right- and left-handed operation.

Once a temperature of lower than -175 °C is achieved, a specimen is loaded from the grid box into the holder tip. The holder accepts a 3 mm diameter TEM specimen grid, which is secured by the holder’s one-piece, integrated cradle clamp. The clamp automatically closes when the holder tip is retracted. Optionally, the cradle clamp can be closed with forceps or with the supplied specimen tool. The thin profile of the clamp maximizes specimen visibility, even at high-tilt angles.

The specimen holder tip retracts inside an actively cooled cryo shield located within the holder. This shield prevents any atmospheric water from condensing on the specimen during transfer to or from the microscope.

Rapid cool down, extended hold time

The Cryo Transfer Tomography Holder rapidly reaches a working temperature of less than -175 °C in either the cryo work station or a TEM. Hold times in excess of 4 hours are readily obtained with the 200 ml dewar capacity.

The temperature controller connects directly to the specimen holder dewar and displays the holder tip temperature.

Gallery

  • The modular reservoirs in the cryo work station can be repositioned to accommodate left- or right-hand use.
    Close up view of the cryo work station
    The modular reservoirs in the cryo work station can be repositioned to accommodate left- or right-hand use.
  • The one-piece, integrated cradle clamp automatically closes when the specimen tip is retracted. Clamp is shown in the opened position.
    Tool-free specimen loading; clamp open
    The one-piece, integrated cradle clamp automatically closes when the specimen tip is retracted. Clamp is shown in the opened position.
  •   The one-piece, integrated cradle clamp automatically closes when the specimen tip is retracted. Clamp is shown in the closed position.
    Tool-free specimen loading; cradle clamp closed
    The one-piece, integrated cradle clamp automatically closes when the specimen tip is retracted. Clamp is shown in the closed position.
  • The specimen holder tip retracts inside an actively cooled cryo shield located within the holder.
    Cryo shield
    The specimen holder tip retracts inside an actively cooled cryo shield located within the holder.
  • The Model 2550 Cryo Transfer Tomography Holder inserted into a TEM.
    Holder in TEM
    The Model 2550 Cryo Transfer Tomography Holder inserted into a TEM.