The work wishes to acknowledge support from the National Natural Science Foundation of China (No. 82173976), National Key Research and Development Program (No. 2018YFC1707205), and State Key Laboratory of Innovative Drugs and High Energy Saving Pharmaceutical Equipment, Jiangxi University of Traditional Chinese Medicine (No. GZSYS202003).

1. Preparation of test sample
<ol>
	<li>Set up four different batches of Indigo Naturalis herbal powder for the test. Pass each sample through the seventh sieve and ninth sieve in turn and collect the sample between the seventh and ninth sieve5. 
	NOTE: The average aperture size of the seventh sieve is 125 &#181;m &#177; 5.8 &#181;m. The average aperture size of the ninth sieve is 75 &#181;m &#177; 4.1 &#181;m.</li>
	<li>Accurately weigh 0.2 g of the sample (Indigo Naturalis powder) on a weighing paper and set it aside.</li>
</ol>
2. Sample addition
<ol>
	<li>Build an iron support stand and put an iron ring with a 5 cm diameter funnel on it.</li>
	<li>Use a pipette to add 20 mL of pure water to the sample glass bottle (bottom diameter 2.6 cm, height 6 cm). Place the sample glass bottle directly under the funnel so that the lower edge of the funnel is flush with the mouth of the bottle. 
	NOTE: Clean the exterior of the sample glass vial with a clean, non-abrasive paper towel and inspect the glass surface for visible marks. If there are, change the glass bottle. Be careful not to spill when adding liquid.</li>
	<li>Release the sample at a height of 80 cm from the lower edge of the funnel so that it can slide freely along the funnel into the sample bottle.</li>
</ol>
3. Instrument operation
<ol>
	<li>Turn on the Turbiscan Lab instrument and warm it up for 30 min.</li>
	<li>Create the file. Click the Create file button in the top menu (or the New file function in the File menu) to create a new empty measurement file. Define its name and save location (by default, the data folder is located at: &#34;C:/users/admin/Formulaction/FAnalyser/Data&#34;.</li>
	<li>Click the Show Turbiscan Lab Temperature button in the top menu to set the instrument target temperature to 25 &#176;C. 
	NOTE: The instrument temperature is influenced by the room temperature, so be careful to adjust the ambient temperature.</li>
	<li>Click Program Scan in the top menu to enter the setup analysis program. Add the program to the list, and in the taskbar, add 30 s as a cycle and 21 scans to the analysis sequence. Select this analysis program for all subsequent measurements.</li>
	<li>Move the prepared sample vial into the measurement system. After setting up the program, click Start to start the measurement. 
	NOTE: Be careful not to shake the glass bottle when moving and only move it slightly.</li>
	<li>After data acquisition, click on the list of calculated parameters to automatically calculate TSI.</li>
</ol>

<ol>
	<li>Li, G. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+application+of+water+test+in+the+identification+of+traditional+Chinese+medicine.">The application of water test in the identification of traditional Chinese medicine.</a> Chinese Medicine Modern Distance Education of China. 19 (23), 153-155 (2021).</li><li>Ye, B. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Analysis+of+application+effect+of+water+test+method+in+identification+of+traditional+Chinese+medicine.">Analysis of application effect of water test method in identification of traditional Chinese medicine.</a> Heilongjiang Medicine Journal. 33 (02), 283-285 (2020).</li><li>Yang, Q. Y., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=From+natural+dye+to+herbal+medicine:+a+systematic+review+of+chemical+constituents,+pharmacological+effects+and+clinical+applications+of+indigo+naturalis.">From natural dye to herbal medicine: a systematic review of chemical constituents, pharmacological effects and clinical applications of indigo naturalis.</a> Chinese Medicine. 15 (1), 127 (2020).</li><li>Chen, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=The+application+value+of+water+test+method+in+the+identification+of+Chinese+medicine.">The application value of water test method in the identification of Chinese medicine.</a> Journal of Traditional Chinese Medicine Management. 30 (10), 133-134 (2022).</li><li>Liu, X. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Establishment+and+application+of+a+rapid+quality+inspection+method+for+Indigo+Naturalis+based+on+quantitative+portrayal+of+water+testing+process.">Establishment and application of a rapid quality inspection method for Indigo Naturalis based on quantitative portrayal of water testing process.</a> Acta Pharmacologica Sinica. 57 (11), 3411-3418 (2022).</li><li>Mengual, O., Meunier, G., Cayre, I., Puech, K., Snabre, P. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterisation+of+instability+of+concentrated+dispersions+by+a+new+optical+analyser:+the+TURBISCAN+MA+1000.">Characterisation of instability of concentrated dispersions by a new optical analyser: the TURBISCAN MA 1000.</a> Colloids and Surfaces A: Physicochemical and Engineering Aspects. 152 (1), 111-123 (1999).</li><li>Olatunji, O. N., Du, J., Hintz, W., Tomas, J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Application+of+particle+sedimentation+analysis+in+sterically-stabilized+TiO2+particles+stability+assessment.">Application of particle sedimentation analysis in sterically-stabilized TiO2 particles stability assessment.</a> Advanced Powder Technology. 27 (4), 1325-1336 (2016).</li><li>Ferrentino, G., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Fining+of+red+wine+monitored+by+multiple+light+scattering.">Fining of red wine monitored by multiple light scattering.</a> Journal of Agricultural and Food Chemistry. 65 (27), 5523-5530 (2017).</li><li>Ramezani, M., Ferrentino, G., Morozova, K., Scampicchio, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Multiple+light+scattering+measurements+for+online+monitoring+of+milk+fermentation.">Multiple light scattering measurements for online monitoring of milk fermentation.</a> Foods. 10 (7), 1582 (2021).</li><li>Yang, H. B., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+new+approach+to+evaluate+the+particle+growth+and+sedimentation+of+dispersed+polymer+microsphere+profile+control+system+based+on+multiple+light+scattering.">A new approach to evaluate the particle growth and sedimentation of dispersed polymer microsphere profile control system based on multiple light scattering.</a> Powder Technology. 315, 477-485 (2017).</li><li>Zhang, X. X., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Treatment+of+non-high-risk+acute+promyelocytic+leukemia+with+realgar-indigo+naturalis+formula+(RIF)+and+all-trans+retinoid+acid+(ATRA):+study+protocol+for+a+randomized+controlled+trial.">Treatment of non-high-risk acute promyelocytic leukemia with realgar-indigo naturalis formula (RIF) and all-trans retinoid acid (ATRA): study protocol for a randomized controlled trial.</a> Trials. 21 (1), 7 (2020).</li><li>Sugimoto, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+efficacy+and+safety+of+oral+Qing-Dai+in+patients+with+ulcerative+colitis:+a+single-center+open-label+prospective+study.">Clinical efficacy and safety of oral Qing-Dai in patients with ulcerative colitis: a single-center open-label prospective study.</a> Digestion. 93 (3), 193-201 (2016).</li><li>Lin, Y. K., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Clinical+assessment+of+patients+with+recalcitrant+psoriasis+in+a+randomized,+observer-blind,+vehicle-controlled+trial+using+indigo+naturalis.">Clinical assessment of patients with recalcitrant psoriasis in a randomized, observer-blind, vehicle-controlled trial using indigo naturalis.</a> Archives of Dermatology. 144 (11), 1457-1464 (2008).</li><li>Sun, Q., Leng, J., Tang, L., Wang, L., Fu, C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+Comprehensive+review+of+the+chemistry,+pharmacokinetics,+pharmacology,+clinical+applications,+adverse+events,+and+quality+control+of+indigo+naturalis.">A Comprehensive review of the chemistry, pharmacokinetics, pharmacology, clinical applications, adverse events, and quality control of indigo naturalis.</a> Frontiers in Pharmacology. 12, 664022 (2021).</li><li>Yang, Y. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Investigation+and+analysis+of+the+commodity+quality+of+Indigo+Naturalis+herbs+in+Beijing+area.">Investigation and analysis of the commodity quality of Indigo Naturalis herbs in Beijing area.</a> Lishizhen Medicine and Materia Medica Research. 23 (07), 1787-1788 (2012).</li><li>Yao, Z. 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The authors have no conflicts of interest to disclose.

According to traditional Chinese medicine, Indigo Naturalis has the power to clear heat and detoxification, cool blood, eliminate spots, purge fire, and arrest convulsion. Based on randomized double-blind controlled clinical trials11,12,13, Indigo Naturalis is effective in the treatment of psoriasis, ulcerative colitis, and acute promyelocytic leukemia in addition to its traditional treatment of cough and phlegm, hemorrhagic sym...

In traditional Chinese medicine, during the course of disease treatment, the clinical effectiveness of medications and the safety of the course of treatment are directly impacted by the quality of Chinese herbal medicine. Utilizing cutting-edge identification technology, one can assess the efficacy of Chinese herbal medicine and guarantee user safety. The Chinese herbal medicine water test method refers to immersing the herbs in water or solvent, then quickly and precisely determining the medicine&#39;s authenticity by observing the changes in color, size, and shape1.
It was originally a good choice for the identification of Chinese medicine. However, the disadvantage of the traditional water test method is that the accuracy and sensitivity of distinguishing the authenticity of Chinese medicine are low because of the subjectivity of observation by the naked eye2. One of the key medicinal materials used in the water test method is Indigo Naturalis, considered an effective remedy for pediatric hyperthermia, psoriasis, leukemia, and ulcerative colitis3. The genuine Indigo Naturalis floats on the surface of water, and the water does not turn dark blue after shaking. However, the fake Indigo Naturalis has particles that sink, and the water will turn dark blue after shaking4. Its principle is due to hydrophobic and easily floatable indigo, indirubin, and other organic components of high-quality Indigo Naturalis. On the contrary, due to low organic matter, a large amount of lime, and heavy texture, some particles doped with fake Indigo Naturalis will sink quickly5. However, this method is only a simple qualitative identification, and it limits the rapid identification of the authenticity of Chinese herbal medicine and fails to reveal the changes of Indigo Naturalis in water.
Multiple light scattering technology is a technology that can measure multi-angle light signal scanning based on a laser passing through the sample. The incident light will be scattered when it penetrates the sample or encounters particles. If the scattered light penetrates through the sample, a transmission light signal is formed; If the sample concentration is high, the light will be reflected by the particles, forming a backscattering light signal. The changes in light intensity reflect the changes in particle concentration and particle size in liquid preparation6. The multiple light scattering instruments can quickly and accurately analyze phenomena such as emulsification, flocculation, precipitation, and rupture of suspension, emulsion, and foam liquid by multiple light scattering technology, as well as quantitatively analyze characteristics such as the rate of occurrence of the above phenomena.
Multiple light scattering technology has demonstrated significant benefits in particle stability monitoring7, red wine clarification8, and milk fermentation quality control9. Using this technology, the traditional water test method of Indigo Naturalis may be intuitive, quantitative, and scientific. Therefore, based on the principle of multiple light scattering technology, this study established a rapid evaluation method for the quality of Indigo Naturalis, taking the Turbiscan stability index (TSI) of the sample as the index of quality control (Figure 1).

<table><tbody><tr><td>Analytical balance (1/10,000)</td><td>Sartorious, Germany</td><td>BSA224S&amp;nbsp;</td><td>www.sartorius.com.cn</td></tr><tr><td>Funnel</td><td>Chengdu Kelong Chemical Co. LTD</td><td>Diameter 5 cm</td><td>www.cdkelongchem.com</td></tr><tr><td>Indigo Naturalis S1</td><td>Xianyou, Fujian</td><td>20210501</td><td></td></tr><tr><td>Indigo Naturalis S2</td><td>Yaan, Sichuan</td><td>20201102</td><td></td></tr><tr><td>Indigo Naturalis S3</td><td>Xianyou, Fujian</td><td>20161012</td><td></td></tr><tr><td>Indigo Naturalis S4</td><td>Xianyou, Fujian</td><td>20180305</td><td></td></tr><tr><td>&amp;nbsp;Iron ring</td><td>Chengdu Kelong Chemical Co. LTD</td><td>/</td><td>www.cdkelongchem.com</td></tr><tr><td>Iron stand</td><td>Chengdu Kelong Chemical Co. LTD</td><td>/</td><td>www.cdkelongchem.com</td></tr><tr><td>Mili-Q ultra-pure water meter</td><td>Milipore, USA</td><td>Mili-Q</td><td>www.merckmillipore.com</td></tr><tr><td>Ninth sieve</td><td>Chengdu Kelong Chemical Co. LTD</td><td>Average aperture size 75 &amp;micro;m</td><td>www.cdkelongchem.com</td></tr><tr><td>Sample bottle</td><td>French Formulaction Company</td><td>Bottom diameter 2.6 cm, height 6 cm</td><td>www.formulaction.com</td></tr><tr><td>Seventh sieve</td><td>Chengdu Kelong Chemical Co. LTD</td><td>Average aperture size 125 &amp;micro;m</td><td>www.cdkelongchem.com</td></tr><tr><td>Turbisoft Lab multiple light scattering instrument</td><td>French Formulaction Company</td><td>Turbisoft Lab 2.3.1.125 Fanalyser 1.3.5</td><td>www.formulaction.com</td></tr><tr><td>Weighing paper</td><td>Chengdu Kelong Chemical Co. LTD</td><td>/</td><td>www.cdkelongchem.com</td></tr></tbody></table>

fast inspection of quality of indigo naturalis by multiple light scattering

Quality control of Chinese herbal medicine is a crucial component of Chinese herbal medicine research and development. Faced with the challenges of modernization and internationalization of Chinese herbal medicine, it is urgent to establish thorough and effective procedures for quality identification of Chinese herbal medicine, and there is an urgent need for new analytical and testing techniques that are efficient, accurate, and environmentally friendly. 
Multiple light scattering is a cutting-edge and analytical method that can accurately and rapidly assess the quality of Chinese herbal medicine without altering the nature or state of the sample or using organic reagents. Indigo Naturalis is considered a good remedy for pediatric hyperthermia, psoriasis, leukemia, and ulcerative colitis. In this study, the process of addition of Indigo Naturalis powder in water was recorded precisely using a multiple light scattering instrument. 
The qualitative and quantitative measurements of the instrument can be used to accurately capture the overall trajectory and sinking behavior of Indigo Naturalis powder into water and to establish a rapid evaluation method for the quality of Indigo Naturalis with the transmission and backscattering spectrograms of the sample as qualitative indicators and stability index as a quantitative indicator. The analytical technique based on multiple light scattering provides a fast, accurate, green, and environmentally friendly method for the quality evaluation of Indigo Naturalis and supports the development and transformation of high-quality Indigo Naturalis.

Figure 2A-D correspond to S1, S2, S3, and S4 of Indigo Naturalis, respectively. A is of high-quality Indigo Naturalis, showing the same light transmittance at any height within 0-10 min, which is very stable. B is the common Indigo Naturalis, and its light transmittance fluctuates slightly with the change of time and is generally stable. C and D are fake and inferior products. There may be two conditions in the transmission spectrograms of fake Indigo Natura...

Watch this Scientific Journal Video about Fast Inspection of Quality of Indigo Naturalis by Multiple Light Scattering at JoVE.com

Fast Inspection of Quality of Indigo Naturalis by Multiple Light Scattering

Here, we present a quality evaluation method based on a multiple light scattering technique to evaluate the quality of Indigo Naturalis.

Quality control of Chinese herbal medicine is a crucial component of Chinese herbal medicine research and development. Faced with the challenges of ...

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Medicine

362 Views.  Chengdu University of Traditional Chinese Medicine. Here, we present a quality evaluation method based on a multiple light scattering technique to evaluate the quality of Indigo Naturalis.

Video: Fast Inspection of Quality of Indigo Naturalis by Multiple Light Scattering

Measuring Spatially- and Directionally-varying Light Scattering from Biological Material

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the milli-scale structure of barbs and barbules largely determines the directional pattern of reflected light; and through the macro-scale spatial structure of overlapping, curved feathers, these directional effects create the visual texture. Milli-scale and macro-scale effects determine where on the organism's body, and from what viewpoints and under what illumination, the iridescent colors are seen. Thus, the highly directional flash of brilliant color from the iridescent throat of a hummingbird is inadequately explained by its nano-scale structure alone and questions remain. From a given observation point, which milli-scale elements of the feather are oriented to reflect strongly? Do some species produce broader "windows" for observation of iridescence than others? These and similar questions may be asked about any organisms that have evolved a particular surface appearance for signaling, camouflage, or other reasons.
In order to study the directional patterns of light scattering from feathers, and their relationship to the bird's milli-scale morphology, we developed a protocol for measuring light scattered from biological materials using many high-resolution photographs taken with varying illumination and viewing directions. Since we measure scattered light as a function of direction, we can observe the characteristic features in the directional distribution of light scattered from that particular feather, and because barbs and barbules are resolved in our images, we can clearly attribute the directional features to these different milli-scale structures. Keeping the specimen intact preserves the gross-scale scattering behavior seen in nature. The method described here presents a generalized protocol for analyzing spatially- and directionally-varying light scattering from complex biological materials at multiple structural scales.

We present a non-destructive method for sampling spatial variation in the direction of light scattered from structurally complex materials. By keeping the material intact, we preserve gross-scale scattering behavior, while concurrently capturing fine-scale directional contributions with high-resolution imaging. Results are visualized in software at biologically-relevant positions and scales.

Light interacts with an organism's integument on a variety of spatial scales. For example in an iridescent bird: nano-scale structures produce color; the ...

Engineering

Measurement of Particle Size Distribution in Turbid Solutions by Dynamic Light Scattering Microscopy

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a technique used to measure the size distribution of polymer solutions or colloidal particles. Although this technique is widely used for the assessment of polymer solutions, it is difficult to measure the particle size in concentrated solutions due to the multiple scattering effect or strong light absorption. Therefore, the concentrated solutions should be diluted before measurement. Implementation of the confocal optical component in a dynamic light scattering microscope1 helps to overcome this barrier. Using such a microscopic system, both transparent and turbid systems can be analyzed under the same experimental setup without a dilution. As a representative example, a size distribution measurement of a temperature-responsive polymer solution was performed. The sizes of the polymer chains in an aqueous solution were several tens of nanometers at a temperature below the lower critical solution temperature (LCST). In contrast, the sizes increased to more than 1.0 &#181;m when above the LCST. This result is consistent with the observation that the solution turned turbid above the LCST.

A protocol for the direct measurement of particle size distribution in concentrated solutions using dynamic light scattering microscopy is presented.

A protocol for measuring polydispersity of concentrated polymer solutions using dynamic light scattering is described. Dynamic light scattering is a ...

Chemistry

Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light scattering from intraocular lenses (IOLs) using goniophotometer principles. This protocol describes the SLSP platform and how it employs a 360&#176; rotational photodetector sensor that is scanned around an IOL sample while recording the intensity and location of scattered light as it passes through the IOL medium. The SLSP platform can be used to predict, non-clinically, the propensity for current and novel IOL designs and materials to induce light scatter. Non-clinical evaluation of light scattering properties of IOLs can significantly reduce the number of patient complaints related to unwanted glare, glistening, optical defects, poor image quality, and other phenomena associated with the unintended light scattering. Future studies should be conducted to correlate SLSP data with clinical results to help identify which measured light scatter is most problematic for patients that have undergone cataract surgery subsequent to IOL implantation.

Scanning Light Scattering Profiler SLPS Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

This protocol describes the scanning light scattering profiler (SLSP) that enables the full-angle quantitative evaluation of forward and backward scattering of light from intraocular lenses (IOLs) using goniophotometer principles.

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light ...

DNA-magnetic Particle Binding Analysis by Dynamic and Electrophoretic Light Scattering

Isolation of DNA using magnetic particles is a field of high importance in biotechnology and molecular biology research. This protocol describes the evaluation of DNA-magnetic particles binding via dynamic light scattering (DLS) and electrophoretic light scattering (ELS). Analysis by DLS provides valuable information on the physicochemical properties of particles including particle size, polydispersity, and zeta potential. The latter describes the surface charge of the particle which plays major role in electrostatic binding of materials such as DNA. Here, a comparative analysis exploits three chemical modifications of nanoparticles and microparticles and their effects on DNA binding and elution. Chemical modifications by branched polyethylenimine, tetraethyl orthosilicate and (3-aminopropyl)triethoxysilane are investigated. Since DNA exhibits a negative charge, it is expected that zeta potential of particle surface will decrease upon binding of DNA. Forming of clusters should also affect particle size. In order to investigate the efficiency of these particles in isolation and elution of DNA, the particles are mixed with DNA in low pH (~6), high ionic strength and dehydration environment. Particles are washed on magnet and then DNA is eluted by Tris-HCl buffer (pH = 8). DNA copy number is estimated using quantitative polymerase chain reaction (PCR). Zeta potential, particle size, polydispersity and quantitative PCR data are evaluated and compared. DLS is an insightful and supporting method of analysis that adds a new perspective to the process of screening of particles for DNA isolation.

This protocol describes the synthesis of magnetic particles and evaluation of their DNA-binding properties via dynamic and electrophoretic light scattering. This method focuses on monitoring changes in particle size, their polydispersity and zeta potential of particle surface which play major role in binding of materials such as DNA.

Isolation of DNA using magnetic particles is a field of high importance in biotechnology and molecular biology research. This protocol describes the ...

A Rapid and Chemical-free Hemoglobin Assay with Photothermal Angular Light Scattering

Photo-thermal angular light scattering (PT-AS) is a novel optical method for measuring the hemoglobin concentration ([Hb]) of blood samples. On the basis of the intrinsic photothermal response of hemoglobin molecules, the sensor enables high-sensitivity, chemical-free measurement of [Hb]. [Hb] detection capability with a limit of 0.12 g/dl over the range of 0.35 - 17.9 g/dl has been demonstrated previously. The method can be readily implemented using inexpensive consumer electronic devices such as a laser pointer and a webcam. The use of a micro-capillary tube as a blood container also enables the hemoglobin assay with a nanoliter-scale blood volume and a low operating cost. Here, detailed instructions for the PT-AS optical setup and signal processing procedures are presented. Experimental protocols and representative results for blood samples in anemic conditions ([Hb] = 5.3, 7.5, and 9.9 g/dl) are also provided, and the measurements are compared with those from a hematology analyzer. Its simplicity in implementation and operation should enable its wide adoption in clinical laboratories and resource-limited settings.

A photo-thermal angular light scattering (PT-AS) sensor enables the rapid and chemical-free hemoglobin assay of nanoliter-scale blood samples. Here, details of the PT-AS setup and a measurement protocol for the hemoglobin concentration in blood are provided. Representative results for anemic blood samples are also presented.

Photo-thermal angular light scattering (PT-AS) is a novel optical method for measuring the hemoglobin concentration ([Hb]) of blood samples. On the basis ...

Bioengineering

Use of Chitosan to Enhance Photoluminescence of Curcumin for Textile Authentication

Enhanced Photoluminescence of Curcuma longa Extracts via Chitosan-Mediated Energy Transfer for Textile Authentication Applications

Dyes for security markings play a pivotal role in safeguarding the integrity of products across various fields, such as textiles, pharmaceuticals, food, and manufacturing among others. However, most commercial dyes used as security markings are costly and may contain toxic and harmful substances that pose a risk to human health. Curcumin, a natural phenolic compound found in turmeric, possesses distinct photoluminescent properties alongside its vibrant yellow color, making it a potential candidate material for authentication applications. This study demonstrates a cost-effective and eco-friendly approach to develop enhanced photoluminescent emissions from curcumin dyes for textile authentication. Curcumin was extracted from C. longa using sonication-assisted-solvent extraction method. The extract was dip-coated and dyed into the textile substrates. Chitosan was introduced as a post-mordanting agent to stabilize the curcumin and as a co-sensitizer. Co-sensitization of curcumin with chitosan triggers energy transfer to enhance its luminescent intensity. The UV-visible absorption peak at 424 nm is associated with the characteristic absorption of curcumin. The photoluminescence measurements showed a broad emission peaking at 545 nm with significant enhancement attributed to the energy transfer induced by chitosan, thus showing great potential as a naturally derived photoluminescent dye for authentication applications.

Author Spotlight: Eco-friendly Photoluminescent Textile Authentication with Curcumin

Photoluminescence is one of the most effective authentication mechanisms being used today. Utilizing and enhancing naturally sourced materials with inherent photoluminescent properties and incorporating them into fabric substrates can lead to development of green, sustainable, and functional textiles for smart applications.

Dyes for security markings play a pivotal role in safeguarding the integrity of products across various fields, such as textiles, pharmaceuticals, food, ...

Evaluation of Photosynthetic Behaviors by Simultaneous Measurements of Leaf Reflectance and Chlorophyll Fluorescence Analyses

Chlorophyll a fluorescence analysis is widely used to measure photosynthetic behaviors in intact plants, and has resulted in the development of many parameters that efficiently measure photosynthesis. Leaf reflectance analysis provides several vegetation indices in ecology and agriculture, including the photochemical reflectance index (PRI), which can be used as an indicator of thermal energy dissipation during photosynthesis because it correlates with non-photochemical quenching (NPQ). However, since NPQ is a composite parameter, its validation is required to understand the nature of the PRI parameter. To obtain physiological evidence for evaluation of the PRI parameter, we simultaneously measured chlorophyll fluorescence and leaf reflectance in xanthophyll cycle defective mutant (npq1) and wild-type Arabidopsis plants. Additionally, the qZ parameter, which likely reflects the xanthophyll cycle, was extracted from the results of chlorophyll fluorescence analysis by monitoring relaxation kinetics of NPQ after switching the light off. These simultaneous measurements were carried out using a pulse-amplitude modulation (PAM) chlorophyll fluorometer and a spectral radiometer. The fiber probes from both instruments were positioned close to each other to detect signals from the same leaf position. An external light source was used to activate photosynthesis, and the measuring lights and saturated light were provided from the PAM instrument. This experimental system enabled us to monitor light-dependent PRI in the intact plant and revealed that light-dependent changes in PRI differ significantly between the wild type and npq1 mutant. Furthermore, PRI was strongly correlated with qZ, meaning that qZ reflects the xanthophyll cycle. Together, these measurements demonstrated that simultaneous measurement of leaf reflectance and chlorophyll fluorescence is a valid approach for parameter evaluation.

We describe a new technical approach to study photosynthetic responses in higher plants involving simultaneous measurements of chlorophyll a fluorescence and leaf reflectance using a PAM and a spectral radiometer for the detection of signals from the same leaf area in Arabidopsis.

Chlorophyll a fluorescence analysis is widely used to measure photosynthetic behaviors in intact plants, and has resulted in the development of many ...

Using Multiple Light Scattering to Examine the Stability of Phyllanthus emblica L. Extracts Obtained with Different Extraction Methods

The extraction intermediate of traditional Chinese medicine is the key intermediate in the preparation process, and its stability has an important impact on the effectiveness and quality of the final product. However, existing stability evaluation methods are often time-consuming and labor-intensive, requiring long-term observation and the operation of complex equipment (such as high-performance liquid chromatography), and it is difficult to obtain more physical information about the instability of the system. Therefore, there is an urgent need to establish a fast and accurate stability analysis technology for traditional Chinese medicine. Multiple light scattering is a cutting-edge analytical method that can accurately and rapidly evaluate the stability of traditional Chinese medicines in an environment-friendly manner without changing the nature or state of the sample or using organic reagents.
In this work, using the precise scanning data of multiple light scattering, the present protocol rapidly acquired the variation curves for layer thickness, particle migration speed, and average particle size over time. This enabled the precise identification of the mechanism and crucial characteristics causing the system&#39;s instability in its early stages. Of note, the research period for the extraction process can be considerably shortened by the detailed quantification of the system stability, which also allows for a quick, accurate, and in-depth analysis of the effects of various extraction processes on the stability of Phyllanthus emblica L.

Using Multiple Light Scattering to Examine the Stability of Phyllanthus emblica L. Extracts Obtained with Different Extraction Methods

Here, we introduce a stability evaluation method based on multiple light scattering technology to evaluate the stability of traditional Chinese medicine extracts.

The extraction intermediate of traditional Chinese medicine is the key intermediate in the preparation process, and its stability has an important impact ...

Dynamic Light Scattering Analysis for the Determination of the Particle Size of Iron-Carbohydrate Complexes

Intravenously administered iron-carbohydrate nanoparticle complexes are widely used to treat iron deficiency. This class includes several structurally heterogeneous nanoparticle complexes, which exhibit varying sensitivity to the conditions required for the methodologies available to physicochemically characterize these agents. Currently, the critical quality attributes of iron-carbohydrate complexes have not been fully established. Dynamic light scattering (DLS) has emerged as a fundamental method to determine intact particle size and distribution. However, challenges still remain regarding the standardization of methodologies across laboratories, specific modifications required for individual iron-carbohydrate products, and how the size distribution can be best described. Importantly, the diluent and serial dilutions used must be standardized. The wide variance in approaches for sample preparation and data reporting limit the use of DLS for the comparison of iron-carbohydrate agents. Herein, we detail a robust and easily reproducible protocol to measure the size and size distribution of the iron-carbohydrate complex, iron sucrose, using the Z-average and polydispersity index.

Dynamic light scattering (DLS) has emerged as a suitable assay for evaluating the particle size and distribution of intravenously administered iron-carbohydrate complexes. However, the protocols lack standardization and need to be modified for each iron-carbohydrate complex analyzed. The present protocol describes the application and special considerations for the analysis of iron sucrose.

Intravenously administered iron-carbohydrate nanoparticle complexes are widely used to treat iron deficiency. This class includes several structurally ...

Autofluorescence Imaging to Evaluate Red Algae Physiology

Red algae (Rhodophyta) contain phycobiliproteins and colonize habitats with dim light, however some (e.g., some Chroothece species) can also develop in full sunshine. Most rhodophytes are red, however some can appear bluish, depending on the proportion of blue and red biliproteins (phycocyanin and phycoerythrin). Different phycobiliproteins can capture light at diverse wavelengths and transmit it to chlorophyll a, which makes photosynthesis under very different light conditions possible. These pigments respond to habitat changes in light, and their autofluorescence can help to study biological processes. Using Chroothece mobilis as a model organism and the spectral lambda scan mode in a confocal microscope, the adaptation of photosynthetic pigments to different monochromatic lights was studied at the cellular level to guess the species' optimal growth conditions. The results showed that, even when the studied strain was isolated from a cave, it adapted to both dim and medium light intensities. The presented method is especially useful for studying photosynthetic organisms that do not grow or grow very slowly under laboratory conditions, which is usually the case for those living in extreme habitats.

The present protocol describes step-by-step autofluorescence imaging and evaluation of phycobiliprotein changes in red algae based on spectral analysis. This is a label-free and non-destructive method to evaluate cellular adaptation to extreme habitats, when only scarce material is available and cells grow slowly, or not at all, under laboratory conditions.

Red algae (Rhodophyta) contain phycobiliproteins and colonize habitats with dim light, however some (e.g., some Chroothece species) can also develop in ...

Fast Inspection of Quality of Indigo Naturalis by Multiple Light Scattering

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