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Zohdi V, Whelan DR, Wood BR, Pearson JT, Bambery KR, Black MJ. Importance of tissue preparation methods in FTIR micro-spectroscopical analysis of biological tissues: 'traps for new users'. PLoS One 2015; 10:e0116491. [PMID: 25710811 PMCID: PMC4339720 DOI: 10.1371/journal.pone.0116491] [Citation(s) in RCA: 82] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2014] [Accepted: 12/10/2014] [Indexed: 11/19/2022] Open
Abstract
Fourier Transform Infrared (FTIR) micro-spectroscopy is an emerging technique for the biochemical analysis of tissues and cellular materials. It provides objective information on the holistic biochemistry of a cell or tissue sample and has been applied in many areas of medical research. However, it has become apparent that how the tissue is handled prior to FTIR micro-spectroscopic imaging requires special consideration, particularly with regards to methods for preservation of the samples. We have performed FTIR micro-spectroscopy on rodent heart and liver tissue sections (two spectroscopically very different biological tissues) that were prepared by desiccation drying, ethanol substitution and formalin fixation and have compared the resulting spectra with that of fully hydrated freshly excised tissues. We have systematically examined the spectra for any biochemical changes to the native state of the tissue caused by the three methods of preparation and have detected changes in infrared (IR) absorption band intensities and peak positions. In particular, the position and profile of the amide I, key in assigning protein secondary structure, changes depending on preparation method and the lipid absorptions lose intensity drastically when these tissues are hydrated with ethanol. Indeed, we demonstrate that preserving samples through desiccation drying, ethanol substitution or formalin fixation significantly alters the biochemical information detected using spectroscopic methods when compared to spectra of fresh hydrated tissue. It is therefore imperative to consider tissue preparative effects when preparing, measuring, and analyzing samples using FTIR spectroscopy.
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Affiliation(s)
- Vladislava Zohdi
- Department of Anatomy & Developmental Biology, Monash University, Clayton, Victoria 3800, Australia
| | - Donna R. Whelan
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - Bayden R. Wood
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - James T. Pearson
- Department of Physiology, Monash University, Clayton, Victoria 3800, Australia
| | - Keith R. Bambery
- Centre for Biospectroscopy and School of Chemistry, Monash University, Clayton, Victoria 3800, Australia
| | - M. Jane Black
- Department of Anatomy & Developmental Biology, Monash University, Clayton, Victoria 3800, Australia
- * E-mail:
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Sullivan MA, Li S, Aroney STN, Deng B, Li C, Roura E, Schulz BL, Harcourt BE, Forbes JM, Gilbert RG. A rapid extraction method for glycogen from formalin-fixed liver. Carbohydr Polym 2014; 118:9-15. [PMID: 25542100 DOI: 10.1016/j.carbpol.2014.11.005] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2014] [Revised: 10/17/2014] [Accepted: 11/09/2014] [Indexed: 10/24/2022]
Abstract
Liver glycogen, a highly branched polymer, acts as our blood-glucose buffer. While past structural studies have extracted glycogen from fresh or frozen tissue using a cold-water, sucrose-gradient centrifugation technique, a method for the extraction of glycogen from formalin-fixed liver would allow the analysis of glycogen from human tissues that are routinely collected in pathology laboratories. In this study, both sucrose-gradient and formalin-fixed extraction techniques were carried out on piglet livers, with the yields, purities and size distributions (using size exclusion chromatography) compared. The formalin extraction technique, when combined with a protease treatment, resulted in higher yields (but lower purities) of glycogen with size distributions similar to the sucrose-gradient centrifugation technique. This formalin extraction procedure was also significantly faster, allowing glycogen extraction throughput to increase by an order of magnitude. Both extraction techniques were compatible with mass spectrometry proteomics, with analysis showing the two techniques were highly complementary.
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Affiliation(s)
- Mitchell A Sullivan
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Shihan Li
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Samuel T N Aroney
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Bin Deng
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China.
| | - Cheng Li
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Eugeni Roura
- The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
| | - Benjamin L Schulz
- School of Chemistry and Molecular Biosciences, The University of Queensland, Brisbane, QLD 4072, Australia.
| | - Brooke E Harcourt
- Glycation and Diabetes Complications, Mater Research-UQ, Translational Research Institute, Woolloongabba, QLD 4102, Australia.
| | - Josephine M Forbes
- Glycation and Diabetes Complications, Mater Research-UQ, Translational Research Institute, Woolloongabba, QLD 4102, Australia; Mater Clinical School, University of Queensland, Brisbane, QLD 4072, Australia.
| | - Robert G Gilbert
- Tongji School of Pharmacy, Huazhong University of Science and Technology, Wuhan, Hubei 430030, China; The University of Queensland, Centre for Nutrition and Food Sciences, Queensland Alliance for Agriculture and Food Innovation, Brisbane, QLD 4072, Australia.
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