A highly uniform UV transillumination imaging system for quantitative analysis of nucleic acids and proteins

Extraction Optimization and Bioactivity of Polysaccharides from Ganoderma leucocontextum Spores

Background: Oxidative stress is associated with the occurrence and progress of aging. Natural polysaccharides have attracted considerable attention in the field of antioxidants and anti-aging products due to their superior biological activity and low toxicity. Ganoderma leucocontextum is primarily found in the Tibetan plateau region and is classified as a subspecies of Ganoderma. Known as the famous white Ganoderma, it is a precious food and medicine that has potent biological activity, including antitumor, hypoglycemic, and immune regulation. Since available resources are limited, there are few studies on the spore of Ganoderma leucocontextum. Methods: In this work, a polysaccharide (named GLSP) was extracted from the spore of Ganoderma leucocontextum using a fast, simple, efficient, and environmentally friendly extraction process: the three-phase partitioning (TPP) method. Results: The extraction condition was optimized under the Box-Behnken design (BBD): ratio of the solute to the solvent, 1:21.126 (w/v); (NH4)2SO4 concentration, 30% (w/v); ratio of the slurry to tert-butanol, 1:1.945 (v/v); and shaking temperature, 54.136 °C. Furthermore, a polysaccharide termed GLSP-A1 was purified from GLSP by column chromatography. The basic physicochemical properties were analyzed by molecular weight, Fourier transform infrared spectroscopy, monosaccharide composition, and scanning electron microscopy. Conclusions: GLSP-A1 down-regulated the expression of the pro-inflammation cytokines interleukin-6 and interleukin-1β, indicating favorable in vitro anti-inflammatory properties. In vivo, the effect of GLSP-A1 on aging was examined using the Caenorhabditis model. The results showed that GLSP-A1 reduced reactive oxygen species levels and lipofuscin accumulation. In general, these findings improve our understanding of the chemical content and bioactivity of a polysaccharide from Ganoderma leucocontextum spore and highlight the possibility of GLSP-A1 being utilized in dietary supplements for its anti-aging properties.

Optical imaging modalities for biomedical applications

Optical photographic imaging is a well known imaging method that has been successfully translated into biomedical applications such as microscopy and endoscopy. Although several advanced medical imaging modalities are used today to acquire anatomical, physiological, metabolic, and functional information from the human body, optical imaging modalities including optical coherence tomography, confocal microscopy, multiphoton microscopy, multispectral endoscopy, and diffuse reflectance imaging have recently emerged with significant potential for non-invasive, portable, and cost-effective imaging for biomedical applications spanning tissue, cellular, and molecular levels. This paper reviews methods for modeling the propagation of light photons in a biological medium, as well as optical imaging from organ to cellular levels using visible and near-infrared wavelengths for biomedical and clinical applications.

Using digital photography to implement the McFarland method

The McFarland method allows the concentration of bacterial cells in a liquid medium to be determined by either of two instrumental techniques: turbidimetry or nephelometry. The microbes act by absorbing and scattering incident light, so the absorbance (turbidimetry) or light intensity (nephelometry) measured is directly proportional to their concentration in the medium. In this work, we developed a new analytical imaging method for determining the concentration of bacterial cells in liquid media. Digital images of a series of McFarland standards are used to assign turbidity-based colour values with the aid of dedicated software. Such values are proportional to bacterial concentrations, which allow a calibration curve to be readily constructed. This paper assesses the calibration reproducibility of an intra-laboratory study and compares the turbidimetric and nephelometric results with those provided by the proposed method, which is relatively simple and affordable; in fact, it can be implemented with a digital camera and the public domain software ImageJ.

Quantitative colorimetric-imaging analysis of nickel in iron meteorites

A quantitative analytical imaging approach for determining the nickel content of metallic meteorites is proposed. The approach uses a digital image of a series of standard solutions of the nickel-dimethylglyoxime coloured chelate and a meteorite sample solution subjected to the same treatment as the nickel standards for quantitation. The image is processed with suitable software to assign a colour-dependent numerical value (analytical signal) to each standard. Such a value is directly proportional to the analyte concentration, which facilitates construction of a calibration graph where the value for the unknown sample can be interpolated to calculate the nickel content of the meteorite. The results thus obtained were validated by comparison with the official, ISO-endorsed spectrophotometric method for nickel. The proposed method is fairly simple and inexpensive; in fact, it uses a commercially available digital camera as measuring instrument and the images it provides are processed with highly user-friendly public domain software (specifically, ImageJ, developed by the National Institutes of Health and freely available for download on the Internet). In a scenario dominated by increasingly sophisticated and expensive equipment, the proposed method provides a cost-effective alternative based on simple, robust hardware that is affordable and can be readily accessed worldwide. This can be especially advantageous for countries were available resources for analytical equipment investments are scant. The proposed method is essentially an adaptation of classical chemical analysis to current, straightforward, robust, cost-effective instrumentation.

RT-PCR analysis of pain genes: use of gel-based RT-PCR for studying induced and tissue-enriched gene expression

Frequently, it is important to ascertain whether a molecule that is involved in one model of pain is also involved in other models of pain. Similarly, it may be important to determine whether a molecule involved in nociception in one tissue is also expressed in other tissues and to ascertain the degree of enrichment. Additionally, before initiating a complex set of experiments or purchasing an expensive immunoassay kit, it may be useful to obtain initial supporting evidence to justify the time and money. Is the transcript for the target receptor, protein, or peptide precursor present in, for example, the dorsal root ganglion? And, if present, how abundant is it? Here is where the power of PCR can be applied to obtain a quick but informative answer. In this chapter, we mainly detail the use of gel-based RT-PCR and also provide suggestions on tissue dissection and interpretation of results. The use of gel-based RT-PCR can address many of the questions of abundance or tissue specificity with a minimum of expense and time.

Comparison of SYPRO Ruby and Flamingo fluorescent stains for application in proteomic research

Fluorescent dyes are widely used for the detection and quantitation of proteins separated by polyacrylamide gel electrophoresis. SYPRO Ruby is one such fluorescent dye widely used for this purpose. More recently, another fluorescent dye, Flamingo, is available for expression proteomic research. Using a standard ultraviolet (UV) transilluminator and a charge-coupled device (CCD)-based imaging system, the relative sensitivity of these two different fluorescent stains with regard to detection of protein spots separated by two-dimensional gel electrophoresis (2D-GE) and identification by liquid chromatography-electrospray ionization-tandem mass spectrometry (LC-ESI-MS/MS) were compared. Using mouse kidney and liver homogenates as well as Escherichia coli extract, we detected a greater number of protein spots using Flamingo compared with SYPRO Ruby. In addition, when we compared the number of matched peptides and the percentage of amino acid residues identified for 22 different protein spots of mouse kidney proteome, we observed a higher number of matched peptides and a higher percentage of amino acid residues for the majority of the proteins using Flamingo compared with SYPRO Ruby. Also, we were able to characterize a protein spot that can be detected by Flamingo only. Therefore, we recommend Flamingo over SYPRO Ruby to be used for studies on expression proteomics.

Design and demonstration of a small-animal up-conversion imager

This first small-animal up-conversion imager (SAUCI) was developed and used for in-vivo imaging of up-converting nanoparticles (UCNs.) Unlike traditional fluorophores, UCNs absorb multiple lower-energy photons and emit a single higher-energy photon. This unique physical process makes it possible to image deeper into tissue with lower background signals. In vivo imaging of particle accumulation in the liver was demonstrated following intravenous injection of particles.