Pretreatment of biological sample for microchip analysis

2007 ◽  
pp. 23-57
Author(s):  
Jerome P. Ferrance ◽  
James P. Landers
Keyword(s):  
Biological Sample

Scanning tunneling microscopy of E. coli RNA polymerase deposited onto an Au substrate by an electrochemical process

1991 ◽  
Vol 49 ◽  
pp. 378-379
Author(s):  
Rebecca W. Keller ◽  
Carlos Bustamante ◽  
David Bear
Keyword(s):  
Scanning Tunneling Microscope ◽  
Biological Sample ◽  
Substrate Surface ◽  
Electrochemical Process ◽  
Atomic Resolution ◽  
Scanning Tunneling ◽  
Tunneling Microscopy ◽  
Tunneling Microscope ◽  
E Coli ◽  
Preparation Techniques

Under ideal conditions, the Scanning Tunneling Microscope (STM) can create atomic resolution images of different kinds of samples. The STM can also be operated in a variety of non-vacuum environments. Because of its potentially high resolution and flexibility of operation, it is now being applied to image biological systems. Several groups have communicated the imaging of double and single stranded DNA.However, reproducibility is still the main problem with most STM results on biological samples. One source of irreproducibility is unreliable sample preparation techniques. Traditional deposition methods used in electron microscopy, such as glow discharge and spreading techniques, do not appear to work with STM. It seems that these techniques do not fix the biological sample strongly enough to the substrate surface. There is now evidence that there are strong forces between the STM tip and the sample and, unless the sample is strongly bound to the surface, it can be swept aside by the tip.

Image Formation from Frozen Hydrated Samples in an Energy-Filter-Microscope

1997 ◽  
Vol 3 (S2) ◽  
pp. 1081-1082
Author(s):  
I. Angert ◽  
W. Jahn ◽  
K.C. Holmes ◽  
R.R. Schröder
Keyword(s):  
Biological Sample ◽  
Phase Contrast ◽  
Contrast Ratio ◽  
Partial Coherence ◽  
Atomic Resolution ◽  
Phase Approximation ◽  
Zero Energy ◽  
Contrast Transfer Function ◽  
Weak Phase ◽  
Definition Of

Understanding the contrast formation mechanism in the EM is one of the prerequisites for artefact-free reconstruction of biological structures from images. We found that the normally used correction of contrast formation applied to zero energy loss filtered images corrupted spatial resolution. Therefore the contribution of contrast formed by inelastic electrons was reconsidered, including partial coherence of inelastically scattered electrons and lens aberrations of the microscope. Based on this, a complete description of the zero-loss contrast transfer function (CTF) is now possible.We used tobacco mosaic virus (TMV), a biological sample known at atomic resolution, for definition of optimum CTF-parameters to reconstruct defocus series from an EFTEM LEO 912. CTF theory as known so far describes image contrast in the weak phase approximation as a linear sum of amplitude and phase contrast. The contribution of amplitude contrast (ratio of amplitude to phase contrast A/P) was determined to be between 7% and 5 % for unfiltered images and 12-14 % for zero-loss filtered images. However, in a filter microscope we remove electrons from the image, so we expect a higher amplitude contrast than in non-filtered images.

Synthesis and characterization of a new magnetic restricted access molecularly imprinted polymer for biological sample preparation

2020 ◽  
Vol 24 ◽  
pp. 101002 ◽  
Author(s):  
Tássia Venga Mendes ◽  
Lidiane Silva Franqui ◽  
Mariane Gonçalves Santos ◽  
Célio Wisniewski ◽  
Eduardo Costa Figueiredo
Keyword(s):  
Sample Preparation ◽  
Molecularly Imprinted Polymer ◽  
Biological Sample ◽  
Synthesis And Characterization ◽  
Imprinted Polymer ◽  
Molecularly Imprinted ◽  
Restricted Access

Surface plasmon resonance biosensing toward real biological sample analysis

2009 ◽  
Author(s):  
Audrey Cunche ◽  
Olivier R. Bolduc ◽  
Jean-Francois Masson
Keyword(s):  
Surface Plasmon Resonance ◽  
Surface Plasmon ◽  
Plasmon Resonance ◽  
Biological Sample ◽  
Sample Analysis

A technique for microsecond heating and cooling of a thin (submicron) biological sample

2002 ◽  
Vol 31 (5) ◽  
pp. 378-382 ◽  
Author(s):  
Bradley Steel ◽  
Marcela Bilek ◽  
David McKenzie ◽  
Cristobal dos Remedios
Keyword(s):  
Biological Sample ◽  
Heating And Cooling

scholarly journals Biomarkers in COPD – Challenging, Real or Illusive

Folia Medica ◽  
2018 ◽  
Vol 60 (3) ◽  
pp. 351-363
Author(s):  
Radostina V. Cherneva ◽  
Dimitar T. Kostadinov
Keyword(s):  
Respiratory Tract ◽  
Disease Severity ◽  
Biological Samples ◽  
Biological Sample ◽  
Respiratory Medicine ◽  
European Medicines Agency ◽  
Tissue Sampling ◽  
Huge Amount ◽  
Biomarker Research

Abstract Biomarker research in COPD is becoming the most rapidly progressing sphere in respiratory medicine. Although “omics” generate a huge amount of biomarkers, fibrinogen is the only one validated by the European Medicines Agency. Thousands of studies analyzing different biological samples from the respiratory tract, collected in different ways, using various kits and techniques are generating more and more data, rendering biomarkers very confusing rather than having practical value. It seems that in order to be applicable and validated, biomarkers should be analysed in an accurately described cohort of patients, homogeneous in disease severity and activity. As COPD has multiple mechanisms of pathobiology it raises the issue of which is the most appropriate biological sample reflecting each of them. Unified criteria for tissue sampling, validated kits for respiratory tract probes and standardized technologies should be announced. The review presents the biomarkers that are currently validated and raises the problem of standardization.

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