The Integrative Molecular Analysis Core (IMAC)

The IMAC is housed on the ground floor of the College of Pharmacy and provides the UNM Center for Metals in Biology and Medicine investigators and members with the necessary expertise and tools for a variety of modern molecular analyses, including ICP-MS, EPR spin-trapping, and quantitative mass spectrometry.

Beyond providing access to the advanced analytical instrumentation present in facility, the Core provides in-house analyses, supports innovative protocol development, and provides training to students, fellows, and faculty in the integrated applications associated with the instrumentation. The IMAC is open to all scientists interested in using novel instrumentation to investigate environmental health-related questions. See below for details on the technologies and instrumentation present at the IMAC facility.

Dr. Feng is the Director of the IMAC and an expert in biochemistry and biophysics of metalloproteins, with an emphasis on structural-dynamics-functional relationship. The focus of his laboratory lies at the intersection of physics, chemistry and biology, with a particular emphasis on the molecular biophysics of oxidoreductase enzymes. His primary research focus is on regulation mechanism of nitric oxide synthase (NOS), a flavo-hemoprotein responsible for biosynthesis of nitric oxide (NO), a ubiquitous signaling and effector molecule in mammalian cell biology.

Current Instrumentation and Technologies

The ICP-MS is equipped with a dynamic reaction cell to significantly minimize mass interferences. The ICP-MS, found in a clean room at the COP, is used for biospecimen analyses, ensuring minimal interference (e.g. false positives due to molecular mass interference from our highly mineralized southwestern environment). One of the many examples of how we use the ICP-MS is for the analysis of uranium and related metals concentrations in human urine and blood.

Uniquely, the Nexera has the capability of stably operating with no organic solvent systems, due to the proprietary intelligent heat balancer. In high sample volume laboratories, the maximum sample number for unattended operation is as important as the analysis speed. The Nexera Rack Changer II accommodates up to 12 sample plates (96-well, 384-well, vial plates) to allowing up to 4608 samples to be continuously analyzed unattended. The Rack Changer II incorporates fine temperature control with a cooling function (4 to 40°C) to minimize sample degradation during the process, which is particularly important for biological samples.

The spectrometer is equipped with a standard TE102 resonator, and variable temperature control system and is primarily used for the measurement of small samples, such as chemical solutions, tissue homogenates, tissue slices, and cultured cells. The Bruker ELEXSYS- II E-540 EPR spectrometer is equipped with a L-band bridge (1.0 GHz, low frequency), which allows us to acquire in vivo spectroscopy and imaging of free radical formations in small animal models such as rats and mice. The Bruker gradient system can produce field gradients of more than 40 G/cm (0.40 T m-1) giving submillimeter resolution for EPR imaging. The system incorporates full digital gradient control for precise setting of imaging projection angles. Three resonators are available depending on the nature of the study. One is a specifically designed and constructed 23mm internal birdcage resonator for in vivo studies and imaging for small animals such as mice. Another is a 34mm internal birdcage resonator for in vivo studies and imaging of small animals such as whole body of mice or rat brain. The third resonator, an external loop gap or surface coil resonator constructed by Bruker Biospin, enables the loop to be positioned over the area of interest, providing localized measurement on the specific site of interest on the animal. Each EPR spectrometer has its own dedicated digital data acquisition system which is PC/Linux based with Bruker Xepr data acquisition software.

A Q-Exactive Orbitrap with Nanospray and Vanquish UHPLC will enable several key new functions essential to understanding metals-related biological effects, including identification of conventional and novel oxidative DNA adducts.