Lab Members


Michael Kruer, MD - Sanford Research
Michael Kruer, MD 
Associate Scientist

Dr. Kruer is an Associate Scientist in the Children’s Health Research Center at Sanford Research, an attending pediatric neurologist at Sanford Children’s Hospital, and an Assistant Professor of Pediatrics, and Neurosciences at the University of South Dakota Sanford School of Medicine. The primary focus of Dr. Kruer’s research is to characterize the mechanisms underlying movement disorders and neurodegenerative diseases in order to develop targeted therapies. A second area of interest is neurologic autoimmunity.

Before joining the Children’s Health Research team at Sanford, Dr. Kruer completed his undergraduate studies at Arizona State University and obtained his MD at the University of Arizona College of Medicine. He performed postdoctoral work at Translational Genomics in Phoenix, AZ before training in pediatrics at Phoenix Children’s Hospital. Dr. Kruer completed a fellowship in pediatric neurology and developmental pediatrics at Oregon Health & Science University where he also obtained further postdoctoral training in molecular neurogenetics. Dr. Kruer also completed a fellowship in clinical neuroimmunology while at OHSU.

Marianna Madeo, PhD
Postdoctoral Fellow
Marianna joined the Kruer lab after a postdoctoral fellowship in Biochemistry at the University of Calabria, Italy where she also obtained her doctoral degree. Her PhD work has focused on the optimization of baculovirus expression systems for membrane proteins, and she brings expertise spanning a variety of eukaryotic systems to her current research. Dr. Madeo’s studies focus on the physiological role of yeast orthologs of neurodegenerative disease genes and the in vitro characterization of mutations identified by whole exome sequencing in patients with movement disorders. 
 Nadia Sahir
Nadia Sahir, PhD
Staff Scientist

Dr. Sahir earned her Ph.D in Neurobiology from the University of Paris VII in France. Her primary research interests are directed toward understanding the basis of molecular and cellular mechanisms involved in brain development and disease. In the Kruer lab, Nadia applies her expertise in neurodegenerative diseases to elucidate and understand the molecular and cellular substrates of juvenile parkinsonism using a newly developed mouse model.”

Tyler Jepperson
Lab Manager

A Sioux Falls native, Tyler graduated from Augustana College in 2007 with a BA in Biology and began working for Sanford Research.  He has previously worked in the Sanford Cancer Biology Research Center and Cardiovascular Health Research Center. Tyler is well-trained in a variety of molecular biological and biochemical techniques. He currently serves as lab manager for the Kruer laboratory whilst pursuing pioneering studies of neurogenetic diseases.

 Sanford Research - Lauren Fields
Lauren Fields
Research Associate

Lauren earned her BA in Psychology with a Minor in Neuroscience from Concordia College in Moorhead, MN. Originating from Sioux Falls, she returned to join the Sanford family as a research associate in June of 2012. Before beginning in the Kruer lab, Lauren participated in undergraduate research performing behavioral and gene expression analyses on lupus-prone mice and examining the effects of environmental enrichment on remyelination in the cuprizone mouse model. Lauren builds upon these experiences in the laboratory as she investigates the role of autoantibodies in the pathology of pediatric neurological diseases. Lauren also studies a newly developed mouse model of juvenile parkinsonism.

Sanford Research - Anna Yarrow
Anna Yarrow
Research Associate

Raised in Sioux Falls, Anna is a recent graduate of Northwestern College, Orange City, IA where she obtained her BA in Biology Health Professions. During her undergraduate education, Anna completed research at SDSU studying the cloning capabilities and expression of a mutated strain of the human histone 3 protein. As a research associate in Dr. Kruer’s lab, Anna works on the molecular genetic basis of dystonia and parkinsonism, applying a yeast model of these diseases to study crucial molecular pathways.

Josh Doorn
Medical Student 
After graduating from Sioux Falls Washington High School, Josh obtained a B.S. in Chemistry at the University of South Dakota. During his undergraduate career, he performed research in the Chemistry Department at the University of South Dakota and at International Specialty Products in Wayne, New Jersey. Before beginning medical school, Josh spent a summer in the Kruer Lab researching a mouse model of an early-onset form of Parkinson’s disease. Currently, Josh is performing comparative studies of mitochondrial function in several neurodegenerative disease using patient-derived fibroblasts as a member of the USD Scholarship Pathways program. Josh’s work is supported by a summer fellowship from the American Parkinson Disease Association