These pages describe the development of a set of cryo-tools by the Macromolecular Crystallography (MC) group in collaboration with Hakon Hope for manual manipulation of crystalline samples in liquid nitrogen. The cryo-tools are compatible with the Stanford Auto-Mounter (SAM) system. For instructions on how to use the cryo-tools for freezing and storing samples, see the Cryo-Tools Manual.
The SSRL style magnetic pins are mounted on a strong magnetic base (Fig. 1). The pins are made from solid copper and have a cone shape for reduction of turbulence. The pin is shaped to fit on a standard magnetic mount and can be easily inserted into a standard cryo-vial for storage. The SSRL tongs cover the full pin without the danger of clipping the loop or damaging the sample.
Figure 1. Copper cryo-pin mounted on magnetic base of goniometer head.
The cryo-vial (Fig. 2) is used for cryogenic storage and transportation of crystals mounted in loops on SSRL pins. It consists of a 2 ml Nalgene cryogenic vial that has been modified to fit SSRL cryo-pins and to vent nitrogen gas. Vials are available from Fisher Scientific. (2.0 ml, 1/2" x 1 7/8" O.D.x H, NIN 50011-0020, Cat. # 03-337-7P)
Figure 2. Cryo-vial with cap for storing sample pins.
Cryo-Vial Cap Remover
The SSRL cryo-vial cap remover (Fig. 3) is used to easily remove cryo-vial lids while under liquid nitrogen. It can also be used to screw on a cap under liquid nitrogen.
Figure 3. Cryo-cap remover.
The SSRL cryo-tong (Fig 4) is designed such that it fits the SSRL pin. The tongs cover the full pin without the danger of clipping the loop or damaging the sample.
Figure 4. SSRL-style cryo-tong.
The cryo-magnetic wand is used to transport SSRL pins (Fig 5). While under liquid nitrogen, an SSRL cryo-vial is held with the cryo-vial hemostat, the lid is removed and then the magnetic wand is used to remove and insert SSRL pins. The pin is held on the wand before the pin is picked up and transferred to the cryo-stream using pre-cooled cryo-tongs.
Figure 5. Cryo magnetic wand for transferring sample pins under liquid nitrogen.
Schematic and Assembly
The SSRL cryo-vial hemostat is used to manipulate cryo-vials under liquid nitrogen (Fig 6).
Figure 6. Cryo-tongs for manipulating cryo-vials under liquid nitrogen.