EPR Spectroscopy

EPR spectroscopy is a versatile, noninvasive analytical technique, which can be used for a variety of applications in biology, medicine, and physics to monitor oxidation and reduction processes, biradicals and triplet states, and reaction kinetics. Molecules that can be studied by EPR are most transition metal ions (Fe, Ni, Cu, Mn, …) including hemes and iron-sulfur clusters, protein side chain radicals (Tyr, Trp, Gly, Cys,…), radical states of cofactors (Semiquinones, Flavins, …), inorganic radicals (NO, O2•-, O2, HO, …), and spin-traps (to quench short-lived radicals) and spin labels (attached to proteins or nucleic acids for monitoring a specific region or measuring distance). EPR spectroscopy can be applied to any sample that contains an unpaired electron.

  • Bruker Continuous Wave (CW)-Elexsys E500 spectrometer is equipped with X-band (9.4 GHz) microwave bridge, 12” magnet, and the Elexsys Super High Sensitivity Probehead that offers the world record weak-pitch signal-to-noise ratio of 3000:1. The current set-up also includes the cryostat ESR-900, liquid helium transfer tube, temperature controller (ITC503), all of which are from Oxford Instruments, and floor vacuum pump. With this equipment, we can perform EPR analyses at variable temperatures from 4°K to 200°K. 

  • Bruker CW-EMXmicro spectrometer is equipped with X-band microwave bridge, 12” magnet, and the EMX standard Cavity, which is equally well suited for non-lossy and lossy samples. The EMXmicro spectrometer is currently equipped with the cryostat ER4131VT temperature control system, which has a capability of regulating sample temperatures between 120°K and 370° K.

Prices for the Penn Community (FY '17)*:

Initial training: $100/sample – Mandatory for first three days of use
Instrument use: $20/sample
Staff assistance: $150/day – necessary when running EPR machines at liquid helium temperatures


Both instruments are located within the Department at 233 Anatomy-Chemistry Building.


Kathy Valentine



233 Anatomy-Chemistry Building

Prices for the Penn Community*:

Initial training: $100/sample**

Instrument use: $20/sample

Staff assistance: $150/day***


Download a billing form:

.docx or .pdf


includes all schools of Penn as well as HUP, CHOP, and Wistar


mandatory for three days


Staff assistance is necessary when you need to run EPR machines at liquid helium temperatures.