Lane background removal in thin-layer chromatography images using continuous wavelet

This paper describes a new methodology to remove the background of the lanesin Thin-Layer Chromatography (TLC) images aiming at improving subsequentband detection. The storage of the biological samples to be analysed by TLC isusually done via plastic containers. Filter paper is an alternative that allowsreduced costs and higher portability, but with consequences in the image analysisstage due to a lane background alteration. In order to overcome this problem, anegative control lane is generated in every chromatographic plate. After preprocessingand lane detection stages a one-dimensional intensity profile is usedfor integrating lane information and the background influence is removed withthe help of the Continuous Wavelet Transform (CWT) decomposition. Theproposed method was tested in 78 lane images, A band detection algorithm wasapplied on lane profiles, and a superior detection rate was achieved for thebackground removed lanes

Correction of geometrical distortions in bands of chromatography images

This paper presents a methodology for correcting band distortions in Thin-LayerChromatography (TLC) images. After the segmentation of image lanes, theintensity profile of each lane column is spatially aligned with a reference profileusing a modified version of the Correlation Optimized Warping (COW)algorithm. The proposed band correction methodology was assessed using 105profiles of TLC lanes. A set of features for band characterization was extractedfrom each lane profile, before and after band distortion correction, and was usedas input for three distinct one-class classifiers aiming at band identification. In allcases, the best results of band classification were obtained for the set lanes afterband distortion correction

Liquid Extraction Based Surface Sampling: Liquid Microjunction Surface Sampling Probes Coupled with Mass Spectrometry

The direct sampling of analytes from surfaces under atmospheric conditions followed by mass spectrometric analysis is an ever expanding area of scientific research. Atmospheric pressure surface sampling and ionization techniques for mass spectrometry (MS) offer the ability to interrogate samples that could not be studied under vacuum conditions required of more traditional MS surface analysis techniques. The geometry and nature of materials or surfaces that can be analyzed has been greatly expanded as a result. This dissertation characterizes and shows applications of liquid microjunction surface sampling probe (LMJ-SSP) electrospray ionization systems. The presented work compares traditional analytical work flows with novel analytical workflows utilizing LMJ-SSP-MS technology. The increase of throughput and/or chemical information without the sacrifice of analytical figures of merit is shown and discussed. The readout of analytical surfaces; surfaces where analyte has ended up on a surface in a traditional work flow and not just placed there, constitutes the focus of what is presented in the preceding work. Finally the prospects for spatial liquid chromatography-mass spectrometry (LC-MS) as a powerful analytical technology „in wait‟ is discussed and supported by the presented data

Planar chromatography - Current practice and future prospects

Planar chromatography, in the form of thin-layer or high-performance thin-layer chromatography (TLC, HPTLC), continues to provide a robust and widely used separation technique. It is unrivaled as a simple and rapid qualitative method for mixture analysis, or for finding bioactive components in mixtures. The format of TLC/HPTLC also provides a unique method for preserving the separation, enabling further investigation of components of interest (including quantification/structure determination) separated in both time and space from the original analysis. The current practice of planar chromatography and areas of development of the technology are reviewed and promising future directions in the use of TLC/HPTLC are outlined

Spatially Resolved Laser and Thermal Desorption/Ionization Coupled with Mass Spectrometry

The work discussed in this dissertation is aimed at creating novel approaches to chemical imaging that ultimately allow for submicron resolution. This goal has been approached from two direction using laser based desorption and coupling it with an AFM using apertureless tip-enhanced laser ablation/ionization. The second direction was through the development a new approach to thermal desorption based mass spectrometry experiments by using a proximal probe to spatially desorb the surface and ionizing the plume of neutrals using a secondary ionization source at atmospheric pressure. The thermal desorption approach allows for the easy scaling of the technique all the way from the millimeter to the nanometer regime. In the nanometer regime an AFM platform with silicon based heating AFM probes is used to locally desorb material from nanometer sized craters. The final work in this thesis focused on trying to improve laser based desorption through a secondary ionization of the neutrals plume by capturing the laser desorption plume into a liquid and then electrospaying the solution into a MS. The added benefit of being able to capture the desorption plume into a liquid is the ability to carry out post sampling processing of the captured analyte via high performance liquid chromatography. The ability to clean up a sample via HPLC also allow for the detection of isobaric compounds as well as trace level materials which otherwise would be obscured by matrix effects in complicated sample matrixes like tissues. This application of laser desorption with a secondary ionization by capture into a liquid could be envisioned to be applied to AFM based laser desorption techniques where boosting the ionization efficiency is crucial for signal detection

Automatic improvements of images from 1D gel electrophoresis

V této bakalářské práci jsou vysvětleny základní principy elektroforézy a jejích modalit se zaměřením na 1D gelovou elektroforézu. Popisuje analýzu elektroforeogramu a příčiny jeho zkreslení, a uvádí specifikace aplikací metody v mikrobiologii, genomice a proteomice. Praktická část prezentuje vývoj, optimalizaci a výstupy programu pro automatickou analýzu elektroforeogramů, vytvořeného v prostředí Matlab. Analýza zahrnuje detekci linií a proužků v obrazu a výpočet molekulárních hmotností vzorků. Závěr práce tvoří hodnocení účinnosti detekce a přesnosti výpočtu hmotností.In this bachelor’s thesis are explained the basic principles of electrophoresis and its modalities with focusing on 1D gel electrophoresis. It describes analysis of an electrophoreogram and causes of its possible distortion, and states specifications of applications of the method in microbiology, genomics and proteomics. The practical part presents development, optimization and outputs of a programme for automatic electrophoreogram analysis, which was created in Matlab environment. The analysis contains lane and band detection and computation of samples’ molecular weight. The ending of the thesis is constituted by evaluating efficiency of detection and accuracy of weight computation.

Quantitative measurements on TLC plates using CCD detection

EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Structural biology and characterization of the human R2TP, an HSP90 co-chaperone complex

Tesis Doctoral inédita leída en la Universidad Autónoma de Madrid, Facultad de Ciencias, Departamento de Biología Molecular. Fecha de lectura: 13-07-2017Esta tesis tiene embargado el acceso al texto completo hasta el 13-01-201