Chromium Coating for High Resolution Cryo Sem

Abstract

High quality imaging of macromolecular structure of biological samples can be obtained when combining high resolution SEM with advanced thin metal film coating techniques. Because the yield of secondary electron (SE) signal from biological samples is low, a thin layer of fine grain metal film is often necessary to enrich the SE-I signal yield and enhance the contrast of features of interest. Surface topographic contrast depends on the ratio of SE-I/SE-II collection, and the SE-II signal yield depends on the amount and interaction volume of the backscattered electron (BSE) signal (Peters, 1982). Therefore the metals with low BSE yield should be chosen for high resolution SEM coating. Chromium, which has the features of low atomic weight (Z=24) and sufficient SE signal yield, is an appropriate choice and it was first used by Peters (1982) for high resolution SEM imaging. To create a reproducible pure chromium film, a clean vacuum is the most crucial requirement because Chromium will be oxidized very quickly whenever oxygen exists. Oxidized chromium compound is a totally different metal and is low in the SE yield and low in mass. So, in this project, we will attempt to solve the leaking and oxidation problem so that we can get consistent and clean chromium coating.

Funding Agency

• Agency: National Institute of Health (NIH)
• Institute: National Center for Research Resources (NCRR)
• Type: Biotechnology Resource Grants (P41)
• Project #: 3P41RR000570-27S1
• Application #: 2757600
• Budget Start: 1997-10-01
• Budget End: 1998-09-30
• Support Year: 27
• Fiscal Year: 1998

Institution

• Name: University of Wisconsin Madison
• DUNS #: 161202122
• City: Madison
• State: WI
• Country: United States
• Zip Code: 53715

Publications

Mavroudi, Maria; Zarogoulidis, Paul; Porpodis, Konstantinos et al. (2014) Stem cells' guided gene therapy of cancer: New frontier in personalized and targeted therapy. J Cancer Res Ther (Manch) 2:22-33

Malecki, Marek; Putzer, Emily; Sabo, Chelsea et al. (2014) Directed cardiomyogenesis of autologous human induced pluripotent stem cells recruited to infarcted myocardium with bioengineered antibodies. Mol Cell Ther 2:

Malecki, Marek (2014) 'Above all, do no harm': safeguarding pluripotent stem cell therapy against iatrogenic tumorigenesis. Stem Cell Res Ther 5:73

Malecki, Marek; LaVanne, Christine; Alhambra, Dominique et al. (2013) Safeguarding Stem Cell-Based Regenerative Therapy against Iatrogenic Cancerogenesis: Transgenic Expression of DNASE1, DNASE1L3, DNASE2, DFFB Controlled By POLA1 Promoter in Proliferating and Directed Differentiation Resisting Human Autologous Pluripotent J Stem Cell Res Ther Suppl 9:

Malecki, Marek; Tombokan, Xenia; Anderson, Mark et al. (2013) TRA-1-60(+), SSEA-4(+), POU5F1(+), SOX2(+), NANOG(+) Clones of Pluripotent Stem Cells in the Embryonal Carcinomas of the Testes. J Stem Cell Res Ther 3:

Malecki, Marek (2013) Improved targeting and enhanced retention of the human, autologous, fibroblast-derived, induced, pluripotent stem cells to the sarcomeres of the infarcted myocardium with the aid of the bioengineered, heterospecific, tetravalent antibodies. J Stem Cell Res Ther 3:

Malecki, Marek; Dahlke, Jessica; Haig, Melissa et al. (2013) Eradication of Human Ovarian Cancer Cells by Transgenic Expression of Recombinant DNASE1, DNASE1L3, DNASE2, and DFFB Controlled by EGFR Promoter: Novel Strategy for Targeted Therapy of Cancer. J Genet Syndr Gene Ther 4:152

Zarogoulidis, Paul; Darwiche, Kaid; Sakkas, Antonios et al. (2013) Suicide Gene Therapy for Cancer - Current Strategies. J Genet Syndr Gene Ther 4:

Malecki, Marek; Sabo, Chelsea; Putzer, Emily et al. (2013) Recruitment and retention of human autologous CD34+ CD117+ CD133+ bone marrow stem cells to infarcted myocardium followed by directed vasculogenesis: Novel strategy for cardiac regeneration. Mol Cell Ther 1:

Malecki, Marek; Malecki, Bianca (2012) Routing of Biomolecules and Transgenes' Vectors in Nuclei of Oocytes. J Fertili In Vitro 2012:108-118