Fluorescence Correlation Spectroscopy (FCS): A Promising Tool for Biological Research

Abstract

Fluorescence correlation spectroscopy (FCS) is an important biophysical technique. FCS is currently being used in many areas of biology to solve several scientific problems. Its properties such as detection at the single molecular level, higher sensitivity, and use of lower sample volume make FCS a promising molecular diagnostic tool. The promising applications of FCS extend from DNA kinetics/dynamics studies to the comprehensive understanding of receptor–ligand interactions. In this article, we review various promising biological applications of FCS.     

Diagnosis of colorectal cancer using Raman spectroscopy of laser-trapped single living epithelial cells

A single-cell diagnostic technique for epithelial cancers is developed by utilizing laser trapping and Raman spectroscopy to differentiate cancerous and normal epithelial cells. Single-cell suspensions were prepared from surgically removed human colorectal tissues following standard primary culture protocols and examined in a near-infrared laser-trapping Raman spectroscopy system, where living epithelial cells were investigated one by one. A diagnostic model was built on the spectral data obtained from 8 patients and validated by the data from 2 new patients. Our technique has potential applications from epithelial cancer diagnosis to the study of cell dynamics of carcinogenesis.     

A Matlab based interface for infrared thermographic diagnosis of pediatric musculoskeletal injuries

Background and objectiveOne of the main causes of emergency medical consultations done by children are musculoskeletal injures. In such cases, radiological tests are a common practice to diagnose the gravity of the trauma and determine the likely existence of a fracture. In order to avoid, or at least to reduce, the use of ionizing radiations with children, the infrared thermographic technique was studied as an alternative solution, since it is a non-harmful, non-invasive and non-contact technique, without excessive technical complications and moderate cost when compared to other types of imaging tools.MethodologyWhen an infrared thermographic diagnostic test is performed, and once the pictures of the studied limb are taken accordingly to the established methodology, an imaging post-processing protocol becomes necessary to make a correct interpretation and diagnosis. Aimed at performing the analysis in situ and in real time, in this work we present a software tool based on a Matlab interface. The software programming is based on the results obtained in clinical tests, where several variables were took into consideration. The program is able to determine the probability of fracture basing the diagnosis on a non-linear cataloguing approach, using decision trees.ResultsThe tool implemented allows to diagnose musculoskeletal injures in children shortly after taking the infrared thermographic picture.ConclusionsThe diagnosis tool provides the means for the interpretation of the IT pictures, allows to obtain a diagnosis in a fast way, and may help to decrease the radiation doses in children.     

Near-Infrared Spectroscopy: Effective Tool for Screening of Polymorphs in Pharmaceuticals

Abstract

Near-infrared (NIR) spectroscopy has emerged as an important technique for the screening and characterization of polymorphs in pharmaceuticals. Polymorphism, the ability of a substance to exist in two or more crystalline phases having different physicochemical and biopharmaceutical parameters, has attracted pharmaceutical scientists due to the patentability of new forms. Transformation of the solid phase due to polymorphic changes during manufacturing and storage may lead to formulation hurdles. Vibrational spectroscopy, particularly NIR spectroscopy, is a widely used technique for polymorphs screening in drug development processes and has emerged as a process analytical technology tool. In this review, a brief overview of NIR spectroscopy, chemometric tools, and polymorphs screening of pharmaceuticals using NIR spectroscopy is presented. Recent developments in NIR spectroscopy instrumentation are also discussed.     

K-shell aluminum resonance line ratios for plasma diagnosis using spot spectroscopy

Using a detailed atomic model of K shell aluminum ions, we have calculated four diagnostic resonance line ratios as a function of temperature and density for cylindrical aluminum plasmas of diameter 50 and 100 μm, assumed in collisional-radiative equilibrium. The ion densities vary from 10¹⁹ cm^-3 to 10²¹ cm^-3, the temperatures range from 200 to 700 eV. The conditions are applicable to experiments using the spot spectroscopy technique for plasma diagnosis.     

Raman Spectroscopy Can Detect and Monitor Cancer at Cellular Level: Analysis of Resistant and Sensitive Subtypes of Testicular Cancer Cell Lines

Abstract: Raman spectroscopy has been applied to analyze testicular cancer cell lines. Spectral differences between resistant and sensitive subtypes of testicular cancer cell line 833k samples were successfully analysed. The technique allowed reproducible and quantitative analysis of the specimen and illustrated the chemical specifications of the samples precisely. Six pairs of testicular cancer cell line 833k were studied and the findings were backed by statistical methods; that is, partial least squares discriminant analysis (PLS-DA).

It was concluded that Raman spectroscopy can objectively differentiate between resistant and sensitive cell lines. These results suggest that in the future it may be possible to use cell lines and diagnostic Raman spectroscopy for preoperative classification of biological molecules. Further research is underway to determine whether results obtained from spectroscopic analysis of cell lines can be applied to actual human tissue samples.     

New Approaches and Recent Advances on Characterization of Chemical Functional Groups and Structures,Physiochemical Property,and Nutritional Values in Feedstocks and By-Products: Advanced Spectroanalytical and Modeling Investigations

Abstract: Molecular spectroscopy technique, a rapid and noninvasive analytical technique, is able to reveal biomaterials’ structural features. However, to date, this technique is seldom used in the biofuel and bioethanol processing industry. This article aims to provide research progress and updates on molecular spectroscopy of feedstocks and coproducts from biofuel/bioethanol processing and to show how to use this molecular technique to study the molecular structure, chemical functional groups, and physiochemical properties of feedstocks and coproducts from biofuel processing and how structural changes affect nutrient availability.     

拉曼光谱在癌症诊断中的应用

在各种疾病中癌症的死亡率居第二位。另一方面只要能早期发现和诊断,几乎所有癌症都能治疗。本文介绍拉曼光谱在癌症诊断和抗癌药物筛选中的应用,结果表明拉曼光谱可能识别恶性变化的标记物,在癌症的早期诊断中是一项有用的技术。     

Calibrating Multichannel Raman Spectrometers

Abstract

Although multichannel Raman spectroscopy has a history of more than a decade [I], it was only recently that the real potential of this technique became fully appreciated. The use of advanced optical multichannel detectors (OMDs) is now bringing about a substantial change in Raman spectroscopy. For example, the application of this technique to short-lived transient species has established a new frontier of Raman spectroscopy known as transient and time-resolved Raman spectroscopy [2]. The technique has made it possible to measure the spectrum even from an extremely weak scatterer like a monolayer film deposited on a substrate [3, 41. A recent experiment on an intact mouse lens [5] demonstrated that only 1 mW laser power with 1 s exposure time is enough to obtain a good quality Raman spectrum of the lens protein, which is of clinical importance for the prevention of cataract formation. A number of stimulating reports are also notable in a variety of fields including chemistry, physics, biology, medicine, and engineering. The advantages of multichannel Raman spectroscopy are manifold.     

Breast cancer diagnostics by Raman spectroscopy

This paper presents new results for the normal, malignant and benign tissues by Raman spectroscopy. To the best of our knowledge, this is one of the most statistically reliable research (321 spectra from 44 patients) on Raman spectroscopy-based diagnosis of breast cancers among the world's women population. The paper demonstrates that Raman spectroscopy is a powerful medical diagnostic tool with the key advantage in breast cancer research.     

Fourier Transform Infrared Spectroscopy of Skin Cancer Cells and Tissues

Abstract

The aim of this review is to combine all the information related to the characterization of skin tissues and cells, focusing on the identification of the specific biochemical characteristics of skin cancer. We have characterized two types of melanoma by FTIR spectroscopy: a murine melanoma (B16F10 cell line) and a human melanoma (C8161 cell line). The cells were deposited on IR transparent CaF₂ windows, the spectral range used lay between 900-4000 cm^{? 1}, transmission mode with 2 cm^{? 1} resolution, and 32 scans. A biochemical association is presented for all the absorption bands identified in this study. Besides the characterization of both cell lines above, a collection of works done in the area of skin cancer was also carried out, in this review; some interesting results obtained by different authors with respect to the characterization of different samples (melanomas, follicle sheath, basal cell carcinoma, epidermis tissues, dermis tissue, and human stratum corneum) are presented and compared to the chemical and biological associations performed in each case. The identification of biochemical injuries provides important information that, associated with clinical examination, can assist the diagnosis of diseases. Several FTIR techniques can be used in the diagnosis of biochemical changes in biological tissues, by identifying molecular markers associated with malignant and benign changes or variations in the composition of amino acids in tissues and cells. In the near future, a further study to compare histopatological analysis and biochemical characterization by FTIR spectroscopy would be interesting, in order to verify the accuracy and validate the applicability of this technique in the diagnosis of skin lesions from a statistical viewpoint.     

Near‐infrared Raman spectroscopy for gastric precancer diagnosis

Raman spectroscopy is a molecular vibrational spectroscopic technique that is capable of optically probing the biomolecular changes associated with neoplastic transformation. The purpose of this study was to apply near‐infrared (NIR) Raman spectroscopy for differentiating dysplasia from normal gastric mucosa tissue. A total of 65 gastric mucosa tissues (44 normal and 21 dysplasia) were obtained from 35 patients who underwent endoscopy investigation or gastrectomy operation for this study. A rapid NIR Raman system was utilized for tissue Raman spectroscopic measurements at 785‐nm laser excitation. High‐quality Raman spectra in the range of 800–1800 cm⁻¹ can be acquired from gastric mucosa tissue within 5 s. Raman spectra showed significant differences between normal and dysplastic tissue, particularly in the spectral ranges of 850–1150, 1200–1500 and 1600–1750 cm⁻¹, which contained signals related to proteins, nucleic acids and lipids. The diagnostic decision algorithm based on the combination of Raman peak intensity ratios of I₈₇₅/I₁₄₅₀ and I₁₂₀₈/I₁₆₅₅ and the logistic regression analysis yielded a diagnostic sensitivity of 90.5% and specificity of 90.9% for identification of gastric dysplasia tissue. This work demonstrates that NIR Raman spectroscopy in conjunction with intensity ratio algorithms has the potential for the noninvasive diagnosis and detection of precancer in the stomach at the molecular level. Copyright © 2009 John Wiley & Sons, Ltd.     

RECENT APPLICATIONS OF FLAME ATOMIC ABSORPTION SPECTROMETRY TO ENVIRONMENTAL MEASUREMENTS

ABSTRACT

Atomic absorption spectroscopy is very useful for the determination of a large number of elements, especially at trace levels. It is a widely used technique for analysis of a wide variety of sample matrices including biota, soils, and water. Atomic absorption spectroscopy is a very reputable technique that is inexpensive and delivers accurate results even in a complex matrix. This review focuses on the applications of flame atomic absorption spectroscopy to environmental measurements, and is mainly based on papers published from 1999–2002.     

New Approaches to Generalized Two‐Dimensional Correlation Spectroscopy and Its Applications

Abstract

This review is focused on the recent approaches to generalized 2D correlation spectroscopy, a technique widely used for the analysis of spectral data. A brief introduction of generalized 2D correlation spectroscopy is described first. Then the powerful combination of generalized 2D correlation spectroscopy and multivariate chemometircs techniques, such as the data reconstruction by principal component analysis (PCA), eigenvalue manipulation transformation (EMT), and self‐modeling curve resolution (SMCR) analysis are explored. Examples of successful applications of new approaches to generalized 2D correlation spectroscopy are highlighted.     

Evolved Gas Analysis by Infrared Spectroscopy

Abstract

The analytical applications of the evolved gas analysis (EGA) performed by infrared spectroscopy, for the period extending from 2005 to 2009, are collected in this review. By this technique, the nature of volatile products released by a substance subjected to a controlled temperature program are on-line determined, with the possibility to prove a supposed reaction, either under isothermal or under heating conditions.     

Broad-band dielectric spectroscopy of Ba 2NaNb 5O 15 single crystal

Barium sodium niobate (BNN) single crystals are studied by IR spectroscopy, time-domain THz transmission spectroscopy, HF coaxial wave-guide technique and LF dielectric spectroscopy to cover the frequency range 10²-10¹⁴ Hz in a wide temperature interval. The dielectric response parallel and perpendicular to the polar c-axis is discussed. The ferroelectric transition at T _c = 830 K is driven by a relaxational soft mode coupled with another central-mode type relaxation which both gradually disappear on cooling in the ferroelectric phase. Below T _i the parameters of the expected IR active amplitudon were estimated. The low-temperature permittivity increase on cooling for the field direction has been explained by an incipient proper ferroelectric-ferroelastic transition driven by an IR and Raman active B₂-symmetry soft mode. Received 24 August 2002 Published online 19 December 2002 RID="a" ID="a"e-mail: buixader@fzu.cz     

Medical Application of Raman Spectroscopy

Abstract

In about the last 20 years, Raman spectroscopy has made phenomenal progress owing to technological innovations in lasers, detectors, and computers. Today, application of Raman spectroscopy spreads over large areas of science and technology. Medical science has also become one of the targets of Raman spectroscopy [1]; it has considerable promise as a diagnostic o r analytical tool in medicine since it is an excellent nondestructive structural probe for constituents of biological materials [2–6].     

Study on the Interaction Between Water-Soluble CdTe Quantum Dots and Ovalbumin by Optical Spectroscopy

ABSTRACT

CdTe quantum dots (QDs) modified by 2-mercaptoethylamine hydrochloride (CA) and thioglycolic acid (TGA), respectively, were synthesized in aqueous medium. The interaction of CdTe QDs with ovalbumin has been investigated in depth by Fourier transform infrared spectroscopy (FTIR), UV-Vis absorption, fluorescence-quenching spectrometry, and resonance Rayleigh scattering spectroscopy (RRS). Fluorescence data show that the quenching type of ovalbumin by CA-CdTe QDs is static quenching with the binding constant being 10^?4 M^?1, and the number of binding sites being one. The calculated thermodynamic parameters demonstrate that the main binding forces are hydrophobic interaction and electrostatic attraction. In contrast, the quenching style of ovalbumin by TGA-CdTe QDs is verified to be dynamic quenching. Under suitable acidity conditions, the interaction of CA-CdTe QDs or TGA-CdTe QDs with ovalbumin leads to the remarkable enhancement of RRS, and the increments are found to be proportional to the concentration of ovalbumin in a certain range. A simple and highly sensitive RRS approach for determining ovalbumin is developed. In addition, the causes for the enhancement of RRS and the quenching of fluorescence are investigated to shed light on the quenching mechanism.     

Disease-related proteins determination based on surface-enhanced Raman spectroscopy

Abstract

Surface-enhanced Raman spectroscopy (SERS) is a promising platform for simple, rapid, and economical protein quantitation and analysis and can achieve much lower detection limits for the ultrasensitive detection of proteins and a much wider linear concentration range for quantitative analysis than other methods can. In addition, SERS can provide a large amount of fingerprint information for the individual components of a mixture through SERS effects, which are sensitive and selective for different types of proteins and protein mixtures. In general, the occurrence and development of diseases are accompanied by changes in the content or structure of biomarkers (disease-related proteins). Here, we provide an overview of the SERS technique and its applications to disease-related protein determination. Different diseases, such as Alzheimer’s disease (AD), cardiac muscle tissue injury, and multicancer, are discussed and exhibit potential utility in biomarker detection and diagnosis. SERS opens a new path to the early diagnosis of critical diseases, which will effectively reduce human suffering and mortality.