Consumables and Cryogens

Users are required to purchase their own quartz EPR tubes and cryogens. 

EPR Tube Options:

  • For CW cryostat use, a 4mm OD tube is required.
  • At this time we are supplying 4 mm EPR tubes made in the Chemistry Glass Shop at the rate of $10 per tube. Regular users may also order bulk 4 mm tubes directly through the Glass Shop.
  • Tubes can also be ordered from external suppliers. The Wilmad SQ Thin Wall Precision Tubes have about a 40% rate of fitting into the CW cryostat gastight o-ring (based on previous bulk orders). The Wilmad PQ Thin Wall Precision Tubes have much tighter tolerances and close to 100% of these tubes should fit in the cryostat o-ring. The PQ tubes are significantly more expensive than the SQ tubes, so in the past we have ordered SQ tubes in bulk and established which tubes are suitable for cyrostat use and which are not.
  • Tubes that do not fit in the CW cryostat can be used for room temperature applications.
  • The FT cryostat can accommodate 2, 3, 4 or 5 mm EPR tubes. The OD tolerance is not as important for the FT EPR tubes. 4 mm tubes can be purchased through the Glass Shop, and other size tubes may be ordered from Wilmad.
  • The CW resonator in room temperature mode can accomodate tubes from 2 mm up to 10 mm, in addition to the flat cell and other specialty cells that can be supplied by the user.
  • For caps, we use the narrow side of the white septum for 8 mm tubing, Chem Stores part number 2214383. This can be sealed with parafilm for air-sensitive samples.
  • For extremely air-sensitive samples, tubes can be flame-sealed. Caps and parafilm cannot be used with the FT resonator due to the sample holder. 

Cryostat Quartzware and Specialized Quartzware:

  • The CW cryostat requires an inner quartz sample holder insert, and an outer double-walled quartz dewar. If either piece is broken by a user due to negligence, the user will be charged list price for replacement of the quartware. The inner quartz sample holder is approximately $70, and the double-walled quartz dewar is approximately $650.
  • The flat cell is available for facility users with room temperature aqueous samples. Users are also responsible for replacement of the flat cell if damaged or broken. Current flat cell pricing is approximately $1300. 


  • Liquid nitrogen for EPR applications can be obtained at Chemistry Stores.
  • Liquid helium will be ordered by CIF personnel, and users will be charged the current liter price for helium. Please give staff at least 3 days notice for helium delivery. If possible, the Low Temp Lab prefers a week notice. The cryostat uses liquid helium at a rate of approximately 1-2 L/hr.