Bob Ashley - The Hormel Institute

Bob Ashley
CryoEM Facility Manager


Bob Ashley is the Electron Microscopy Core Facility manager. He is a graduate of Madison College in Madison Wisconsin, which at the time, was one of two professional schools in the nation with a program focused solely on electron microscopy and electron optics. His first position was at the Penn State College of Medicine in Hershey Pennsylvania and received further training at The University of Pittsburgh as an apprentice in the craft of cryo-EM. After 6 years developing a biological cryo-EM core at Penn State, he came back to the Midwest when the Hormel Institute recruited him to run their premier Electron Microscopy facility and has been here since August of 2016.


Electron Microscopy
Madison College

Research Specialties

Specializes in preparing, imaging and solving structures of biological targets with an electron microscope. Targets include individual proteins, complexes, and virus; utilizing single particle cryo-EM techniques and computational mapping.

Research Interests

My research interest is to facilitate the work of scientists exploring biological structures with the hope of discovering not only what they look like, but to ultimately find a deeper understanding of the way they function. Additionally, my focus is on developing the imaging and sample preparation techniques that can progress the capabilities and reach of the craft of the electron cryo-microscopy field in general.


1. Guan J, Bywaters SM, Brendle SA, Ashley RE, Makhov AM, Conway JF, Christensen ND, Hafenstein S. Cryoelectron Microscopy Maps of Human Papillomavirus 16 Reveal L2 Densities and Heparin Binding Site. Structure. 2017 Feb 7;25(2):253-263. doi: 10.1016/j.str.2016.12.001. PubMed PMID: 28065506.

2. Organtini LJ, Shingler KL, Ashley RE, Capaldi EA, Durrani K, Dryden KA, Makhov AM, Conway JF, Pizzorno MC, Hafenstein S. Honey bee deformed wing virus structures reveal conformational changes accompany genome release. J Virol. 2016 Nov 16. pii: JVI.01795-16. [Epub ahead of print] PubMed PMID: 27852845.

3. Lee H, Shingler KL, Organtini LJ, Ashley RE, Makhov AM, Conway JF, Hafenstein S. The novel asymmetric entry intermediate of a picornavirus captured with nanodiscs. Sci Adv. 2016 Aug 24;2(8):e1501929. doi: 10.1126/sciadv.1501929. eCollection 2016 Aug. PubMed PMID: 27574701.

4. Hegarty JP, Sangster W, Ashley RE, Myers R, Hafenstein S, Stewart DB Sr. Induction and Purification of C. difficile Phage Tail-Like Particles. Methods Mol Biol. 2016;1476:167-75. doi: 10.1007/978-1-4939-6361-4_12. PubMed PMID: 27507340.

5. Organtini LJ, Lee H, Iketani S, Huang K, Ashley RE, Makhov AM, Conway JF, Parrish CR, Hafenstein S. The near-atomic resolution structure of a highly neutralizing Fab bound to canine parvovirus. J Virol. 2016 Aug 17. pii: JVI.01112-16. PubMed PMID: 27535057.

6. Guan J, Bywaters SM, Brendle S, Lee H, Ashley RE, Christensen ND, Hafenstein S. The U4 antibody epitope on human papillomavirus 16 identified by cryo-EM. J Virol. 2015 Dec 89(23):12108-17. doi: 10.1128/JVI.02020-15. PMID: 26401038

7. Guan J, Bywaters SM, Brendle SA, Lee H, Ashley RE, Makhov AM, Conway JF, Christensen ND, Hafenstein S. Structural comparison of four different antibodies interacting with human papillomavirus 16 and mechanisms of neutralization. Virology. 2015 Sep 483:253-63. doi: 10.1016/j.virol.2015.04.016. PMID: 25996608

8. Shingler KL, Cifuente JO, Ashley RE, Makhov AM, Conway JF, Hafenstein S. The Enterovirus 71 procapsid binds neutralizing antibodies and rescues virus infection in vitro. J Virol. 2014 Nov 26. PMID: 25941809; PubMed Central PMCID: PMC4420505

9. Lee H, Brendle SA, Bywaters SM, Guan J, Ashley RE, Yoder JD, Makhov AM, Conway JF, Christensen ND, Hafenstein S. A CryoEM study identifies the complete HPV16.V5 epitope and reveals global conformational changes initiated by binding of the neutralizing antibody fragment. J Virol. 2014 Nov 12. PMID: 25392224

10. Lee H, Cifuente JO, Ashley RE, Conway JF, Makhov AM, Tano Y, Shimizu H, Nishimura Y, Hafenstein S. A strain-specific epitope of Enterovirus 71 identified by cryoEM of the complex with Fab from neutralizing antibody. J Virol. 2013 Aug 14. PubMed PMID: 23946455

11. Gullberg M, Muszynski B, Organtini LJ, Ashley RE, Hafenstein SL, Belsham GJ, Polacek C. Assembly and characterization of foot-and-mouth disease virus empty capsid particles expressed within mammalian cells. J Gen Virol. 2013 Jun 5. PubMed PMID: 23740480

12. Cifuente JO, Lee H, Yoder JD, Shingler KL, Carnegie MS, Yoder JL, Ashley RE, Makhov AM, Conway JF, Hafenstein S. The EV71 strain 1095 structures of procapsid and mature virion. J. Virol 2013 May 1. PubMed PMID: 23637404

13. Shingler KL, Yoder JL, Carnegie MS, Ashley RE, Makhov AM, Conway JF, Hafenstein SL. The Enterovirus 71 A-Particle Forms a Gateway to Allow Genome Release: A CryoEM Study of Picornavirus Uncoating. PLoS Pathog. 2013 Mar: 9 (3):e1003240. doi: 10.1371/journal.ppat.1003240. Epub 2013 Mar 21. PubMed PMID: 23555253; PubMed Central PMCID: PMC3605244

14. Ning X, Nguyen D, Mentzer L, Adams C, Lee H, Ashley R, Hafenstein S, Hu J. Secretion of genome-free hepatitis B virus–single strand blocking model for virion morphogenesis of para-retrovirus. PLoS Pathog. 2011 Sep;7(9):e1002255. Epub 2011 Sep 22. PubMed PMID: 21966269; PubMed Central PMCID: PMC3178560

15. Cherwa JE Jr, Organtini LJ, Ashley RE, Hafenstein SL, Fane BA. In Vitro Assembly of the φ174 Procapsid from External Scaffolding Protein Oligomers and Early Pentameric Assembly Intermediates. J Mol Biol. 2011 Aug 5. PubMed PMID: 21840317

Contact Information

Professional memberships

Microscopy Society of America
Institute for Philosophical Studies: Green Bay