Mapping and Measuring DNA to Protein Ratios in Mammalian Sperm Head by XANES Imaging

Zhang, Xiaodong; Balhorn, Rod; Mazrimas, J.A.; Kirz, Janos

doi:10.1006/jsbi.1996.0051

Cited by 140 publications

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“…This indicates a homogeneous distribution of the protein content within the nucleus and the same spatial efficiency of DNA packaging. This is in agreement with earlier results that mapped the protein and DNA distribution within bull sperm cells by high-resolution X-ray imaging [33]. Regardless, all averaged spectra shown in this article were acquired from the central region of the cells.…”

Section: Discussionsupporting

confidence: 92%

“…Aliquots of sperm from this same individual have been examined previously by PIXE (Proton Induced X-ray Emission) and XANES (X-ray Absorption Near Edge Structure) to assess the DNA, protein and zinc content of individual sperm heads [33][34][35]. An aliquot of semen was thawed, washed three times by suspending in 0.01 M Tris pH 8, 0.15 M sodium chloride (T/S) with brief sonication and sedimented by centrifugation for 3 minutes at 4000 g. The cells were resuspended in water and applied to quartz coverslips for analysis.…”

Section: Sample Preparationmentioning

confidence: 99%

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Raman spectroscopy of DNA packaging in individual human sperm cells distinguishes normal from abnormal cells

Huser

Orme

Hollars

et al. 2009

Journal of Biophotonics

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108

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Healthy human males produce sperm cells of which about 25–40% have abnormal head shapes. Increases in the percentage of sperm exhibiting aberrant sperm head morphologies have been correlated with male infertility, and biochemical studies of pooled sperm have suggested that sperm with abnormal shape may contain DNA that has not been properly repackaged by protamine during spermatid development. We have used micro‐Raman spectroscopy to obtain Raman spectra from individual human sperm cells and examined how differences in the Raman spectra of sperm chromatin correlate with cell shape. We show that Raman spectra of individual sperm cells contain vibrational marker modes that can be used to assess the efficiency of DNA‐packaging for each cell. Raman spectra obtained from sperm cells with normal shape provide evidence that DNA in these sperm is very efficiently packaged. We find, however, that the relative protein content per cell and DNA packaging efficiencies are distributed over a relatively wide range for sperm cells with both normal and abnormal shape. These findings indicate that single cell Raman spectroscopy should be a valuable tool in assessing the quality of sperm cells for in‐vitro fertilization. (© 2009 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

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Section: Discussionsupporting

confidence: 92%

Section: Sample Preparationmentioning

confidence: 99%

Raman spectroscopy of DNA packaging in individual human sperm cells distinguishes normal from abnormal cells

Huser

Orme

Hollars

et al. 2009

Journal of Biophotonics

Self Cite

108

View full text Add to dashboard Cite

show abstract

“…29 Quantitative component maps for 10-90% (v/v) EDMA shell compositions are shown in Figure 3. These were derived using singular value decomposition (SVD) 29,40,41 of images at 285.1, 288.4, and 305.1 eV for each species. These results were carefully checked for reproducibility and sensitivity to small changes in the energy and intensity scales of the reference samples.…”

Section: Resultsmentioning

confidence: 99%

Quantitative Compositional Mapping of Core−Shell Polymer Microspheres by Soft X-ray Spectromicroscopy

Koprinarov

Hitchcock

et al. 2001

Macromolecules

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Core-shell polymer microspheres have been prepared by a two-step precipitation polymerization. These microspheres consist of 3.2 µm polydivinylbenzene-55 (DVB55) cores coated with ∼0.4-0.9 µm wide shells composed of poly(DVB55-co-EDMA), a random copolymer of DVB55 and ethylene glycol dimethyl acrylate (EDMA). The chemical composition, core-shell morphology, and porosity of these structured microspheres have been studied quantitatively with scanning transmission X-ray microscopy (STXM) at a spatial resolution of 100 nm. Images recorded at selected energies through the C 1s absorption region were analyzed using singular value decomposition to obtain quantitative maps of the DVB55 and EDMA components. The EDMA concentration in the shell determined by STXM was found to be in good agreement with that predicted from the comonomer composition over the range of 10-90% EDMA. The precision of chemical quantification at high spatial resolution is shown to be adequate for STXM to be useful in guiding the development of structured polymeric systems for particular applications.

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“…Images at all three energies were processed with a singular value decomposition (SVD) procedure 27 to extract quantitative polymer and water thicknesses. This method properly accounts for any gradient in the total water thickness.…”

Section: Resultsmentioning

confidence: 99%

Quantitative Characterization of Microscopic Variations in the Cross-Link Density of Gels

et al. 2001

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We report the visualization and quantitative analysis of the cross-link structure in model core/shell hydrogel polymers on the microscopic scale, in a fully swollen state, using soft X-ray microscopy. The cross-link density in these materials and their microscopic or even nanoscopic variation critically influence materials characteristics, yet the cross-link density is difficult to characterize by conventional methods. By the use of soft X-ray microscopy, one can investigate these materials in a fully swollen state and thus directly visualize and quantitatively determine the cross-link structure on a microscopic scale. Materials that were cross-linked by different methods were shown to give rise to differently shaped profiles. Abrupt and gradient cross-link density profiles have been investigated, and the spatial variation in their cross-link density has been determined quantitatively.

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Mapping and Measuring DNA to Protein Ratios in Mammalian Sperm Head by XANES Imaging

Cited by 140 publications

References 0 publications

Raman spectroscopy of DNA packaging in individual human sperm cells distinguishes normal from abnormal cells

Raman spectroscopy of DNA packaging in individual human sperm cells distinguishes normal from abnormal cells

Quantitative Compositional Mapping of Core−Shell Polymer Microspheres by Soft X-ray Spectromicroscopy

Quantitative Characterization of Microscopic Variations in the Cross-Link Density of Gels

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