نود أن نشكر الدكتور ايفان والدكتور نيويل Bendall شون للوقوف على آرائهم. نود أيضا أن نشكر DVS العلوم والدكتور شون Bendall لعينة من الخرز البوليسترين موضوع متعدد اللانثينيدات التي تحتوي على. ونحن ممتنون للتمويل من المنحة NIH 2 U19 AI057229.

<ol>
	<li>Bandura, D. R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Mass+cytometry:+Technique+for+real+time+single+cell+multitarget+immunoassay+based+on+inductively+coupled+plasma+Time-of-Flight+mass+spectrometry.">Mass cytometry: Technique for real time single cell multitarget immunoassay based on inductively coupled plasma Time-of-Flight mass spectrometry.</a> Anal. Chem. 81, 6813-6822 (2009).</li><li>Lou, X. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Polymer-based+elemental+tags+for+sensitive+bioassays.">Polymer-based elemental tags for sensitive bioassays.</a> Angew. Chem., Int. Ed. 46, 6111-6114 (2007).</li><li>Majonis, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Curious+results+with+palladium-+and+platinum-carrying+polymers+in+mass+cytometry+bioassays+and+an+unexpected+application+as+a+dead+cell+stain.">Curious results with palladium- and platinum-carrying polymers in mass cytometry bioassays and an unexpected application as a dead cell stain.</a> Biomacromolecules. 12, 3997-4010 (2011).</li><li>Leipold, M. D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Development+of+mass+cytometry+methods+for+bacterial+discrimination.">Development of mass cytometry methods for bacterial discrimination.</a> Anal. Biochem. 419, 1-8 (2011).</li><li>Bendall, S. C. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Single-cell+mass+cytometry+of+differential+immune+and+drug+responses+across+a+human+hematopoietic+continuum.">Single-cell mass cytometry of differential immune and drug responses across a human hematopoietic continuum.</a> Science. 332, 687-696 (2011).</li><li>Newell, E. W. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Cytometry+by+Time-of-Flight+shows+combinatorial+cytokine+expression+and+virus-specific+cell+niches+within+a+continuum+of+CD8++T+cell+phenotypes.">Cytometry by Time-of-Flight shows combinatorial cytokine expression and virus-specific cell niches within a continuum of CD8+ T cell phenotypes.</a> Immunity. 36, 142-152 (2012).</li></ol>

الكتاب كل من عمل في مركز الرصد المناعة البشرية، ومركز الخدمة في جامعة ستانفورد التي تهم المستخدم فقط لرسوم استرداد تكلفة المقايسات، بما في ذلك الخلوي الشامل.

على مدى العقود القليلة الماضية، كان التدفق الخلوي مضان طريقة العمود الفقري لتحليل الخلايا واحدة، سواء من حيث التعبير والسطح في المقايسات الفنية. ومع ذلك فقد حد لقضايا التداخل الطيفي لصبغات الفلورسنت عدد علامات في وقت واحد. في حين تم الإبلاغ عن التجارب باستخدام أكثر ...

<table border="1" style=";text-align:right;direction:rtl"><tbody><tr><td> اسم كاشف </td><td> شركة </td><td> كتالوج رقم </td><td> تعليقات </td></tr><tr><td> CyTOF TM الشامل عداد الكريات </td><td> DVS العلوم </td><td></td><td></td></tr><tr><td> غسل الحل </td><td> DVS العلوم </td><td> 201071 </td><td> الهيدروفلوريك حمض 0.05٪ في الماء </td></tr><tr><td> ضبط الحل </td><td> DVS العلوم </td><td> 201072 </td><td> 0.5 جزء في المليون لا، خدمات العملاء، السل، TM، الأشعة تحت الحمراء، تتبع حامض النيتريك </td></tr><tr><td> الخرز البوليسترين الاتحاد الأوروبي التي تحتوي على </td><td> DVS العلوم </td><td> 201073 </td><td> يحتوي الطبيعية وفرة النظائر الاتحاد الأوروبي؛ الخرز المقدمة في حوالي 1 مليون / مل </td></tr><tr><td> متعددة اللانثينيدات التي تحتوي على (لا / العلاقات العامة / السل / تيم / لو) - الخرز البوليسترين </td><td> DVS العلوم </td><td> لم المتاحة تجاريا </td><td> يحتوي الطبيعية وفرة النظائر من اللانثينيدات المدرجة </td></tr><tr><td> حمض النيتريك (مركزة) </td><td> فيشر العلمية </td><td> A467-500 </td><td> أوبتيما تتبع معدن نقي ICP-MS الصف </td></tr><tr><td> البوليسترين جولة القاع أنبوب مع الخلية مصفاة متوسطة 5mL </td><td> BD </td><td> 352235 </td><td> تستخدم لتصفية عينات الخلايا قبل الحقن </td></tr><tr><td> وضع القواعد وJect tuberkulin حقنة-1ML </td><td> هينكه ساس وولف </td><td> 4010-200V0 </td><td> خالية من السيليكون، واللثي خالية </td></tr><tr><td> وضع القواعد وJect حقنة-3 مل </td><td> هينكه ساس وولف </td><td> 4010.000V0 </td><td> خالية من السيليكون، واللثي خالية </td></tr><tr><td> MilliQ المياه </td><td></td><td></td><td> 18 MΩ المياه النقية، ويجب ألا تكون مخزنة في الزجاج أو زجاجات من البلاستيك التي تم غسلها بالمنظفات التجارية (بسبب مستويات عالية من الباريوم الحاضر). </td></tr><tr><td> الذكرranox </td><td> سيغما الدريخ </td><td> Z273236 </td><td> حمض المنظفات </td></tr><tr><td> غاز الأرجون </td><td> PRAXAIR </td><td> AR-T 5.0UH </td><td> 99.999٪ فائق النقاء </td></tr></tbody></table>

mass cytometry: protocol for daily tuning and running cell samples on a cytof mass cytometer

في السنوات الأخيرة، وتحليل السريع للخلايا واحدة وعادة أجريت باستخدام التدفق الخلوي والأجسام المضادة التي تحمل علامات fluorescently. ومع ذلك فقد حد مسألة التداخل الطيفي للانبعاثات fluorophore عدد من التحقيقات في وقت واحد. في المقابل، فإن كتلة CyTOF جديدة عداد الكريات من قبل الأزواج العلوم DVS السائل نظام إدخال وحيدة الخلية إلى 1 ICP-MS. وبدلا من fluorophores، تقترن البوليمرات التي تحتوي على نظائر المعادن مخلبية عالي التخصيب إلى الأجسام المضادة أو تحقيقات أخرى محددة. 2-5 بسبب نقاء المعدن والقرار الجماعي للعداد الكريات الشامل، وليس هناك &quot;تداخل الأطياف&quot; من النظائر المجاورة، وبالتالي لا حاجة للمصفوفات التعويض. بالإضافة إلى ذلك، ونظرا لاستخدام المعادن اللانثينيدات، وليس هناك خلفية البيولوجية وبالتالي لا يعادل تألق ذاتي. مع نافذة تمتد الشامل الكتلة الذرية 103-203، نظريا يمكن تمييز ما يصل الى 100 في وقت واحد التسميات. حاليا، أكثر من 35 قنوات متاحة باستخدام الكواشف مخلبية المتاحة من العلوم DVS، مما يسمح للتشريح لم يسبق لها مثيل من الملف المناعية من العينات. 6-7 عيوب لكتلة الخلوي تتضمن شرط صارمة لنظائر المعادن منفصلة في التحقيق (لا يعادل مبعثر إلى الأمام أو الجانب)، وحقيقة أنها هي تقنية المدمرة (أي إمكانية لاستعادة الفرز). التكوين الحالي للعداد الكريات الشامل لديها أيضا معدل نقل خلية من خلايا فقط ~ 25٪، مما يتطلب إدخال عدد أكبر من الخلايا. الأداء اليومي الأمثل للعداد الكريات الشامل يتطلب العديد من الخطوات. الهدف الأساسي من التحسين هو تعظيم قوة إشارة المقاسة من نظائر المعادن المطلوب (M) مع التقليل من تشكيل أكاسيد (M +16) التي من شأنها أن تقلل من شدة إشارة M وتتداخل مع أي إشارة المرجوة في M +16. الخطوة الأولى هي عملية الاحماء الجهاز بحيث ساخنة، وأنا مستقرةوقد أنشئت CP البلازما. الثانية، يجب أن يكون الأمثل للإعدادات الحالية والمكياج معدل تدفق الغاز على أساس يومي. خلال جمع العينات، ويقتصر هذا الحدث من قبل خلية الحد الأقصى لمعدل الكفاءة للكشف عن وسرعة المعالجة إلى 1000 خلية / ثانية. ومع ذلك، وهذا يتوقف على نوعية العينة، حدث تباطؤ معدل الخلية (300-500 خلية / ثانية) وعادة ما يكون من المرغوب فيه السماح أفضل قرار بين الأحداث الخلايا، وبالتالي تحقيق أقصى قدر من singlets سليمة أكثر من الحلل والحطام. وأخيرا، وتنظيف كافية للآلة في نهاية اليوم يساعد على التقليل من إشارة الخلفية بسبب معدنية مجانية.

وينبغي بعد بروتوكول أعلاه إنجاز أربعة أمور. أولا، سوف يسمح كافية الاحماء الوقت للعداد الكريات الشامل إنتاج الساخنة، والبلازما المستقرة اللازمة لإشارة الأمثل والحد الأدنى من تشكيل أكسيد. والثانية، وغسل كافية من المياه مع عداد الكريات الشامل MilliQ وDVS الحل اغسل (ال...

Watch this Scientific Journal Video about Mass Cytometry: Protocol for Daily Tuning and Running Cell Samples on a CyTOF Mass Cytometer at JoVE.com

Mass Cytometry: Protocol for Daily Tuning and Running Cell Samples on a CyTOF Mass Cytometer

يتم وصف الخطوات الضرورية لضبط اليومية والاستفادة المثلى من أداء عداد الكريات الشامل CyTOF. وتناقش التعليقات على إعداد العينات ومعدل التدفق الأمثل

الخلوي الجماعي: بروتوكول لضبط اليومية وعينات الخلايا تشغيل عداد الكريات الشامل على CyTOF

In recent years, the rapid analysis of single cells has commonly been performed using flow cytometry and fluorescently-labeled antibodies. However, the ...

mass-cytometry-protocol-for-daily-tuning-running-cell-samples-on

Research

JoVE Journal

Bioengineering

22.7K Views.  Stanford University. يتم وصف الخطوات الضرورية لضبط اليومية والاستفادة المثلى من أداء عداد الكريات الشامل CyTOF. وتناقش التعليقات على إعداد العينات ومعدل التدفق الأمثل

Video: Mass Cytometry: Protocol for Daily Tuning and Running Cell Samples on a CyTOF Mass Cytometer

A Simple Hanging Drop Cell Culture Protocol for Generation of 3D Spheroids

Studies of cell-cell cohesion and cell-substratum adhesion have historically been performed on monolayer cultures adherent to rigid substrates. Cells within a tissue, however, are typically encased within a closely packed tissue mass in which cells establish intimate connections with many near-neighbors and with extracellular matrix components. Accordingly, the chemical milieu and physical forces experienced by cells within a 3D tissue are fundamentally different than those experienced by cells grown in monolayer culture. This has been shown to markedly impact cellular morphology and signaling. Several methods have been devised to generate 3D cell cultures including encapsulation of cells in collagen gels1or in biomaterial scaffolds2. Such methods, while useful, do not recapitulate the intimate direct cell-cell adhesion architecture found in normal tissues. Rather, they more closely approximate culture systems in which single cells are loosely dispersed within a 3D meshwork of ECM products. Here, we describe a simple method in which cells are placed in hanging drop culture and incubated under physiological conditions until they form true 3D spheroids in which cells are in direct contact with each other and with extracellular matrix components. The method requires no specialized equipment and can be adapted to include addition of any biological agent in very small quantities that may be of interest in elucidating effects on cell-cell or cell-ECM interaction. The method can also be used to co-culture two (or more) different cell populations so as to elucidate the role of cell-cell or cell-ECM interactions in specifying spatial relationships between cells. Cell-cell cohesion and cell-ECM adhesion are the cornerstones of studies of embryonic development, tumor-stromal cell interaction in malignant invasion, wound healing, and for applications to tissue engineering. This simple method will provide a means of generating tissue-like cellular aggregates for measurement of biomechanical properties or for molecular and biochemical analysis in a physiologically relevant model.

We describe a simple, rapid method of generating 3D tissue-like spheroids and their potential application to quantify differences in cell-cell interactions.

إسقاط خلية بسيطة الشنق بروتوكول الثقافة للجيل 3D الأجسام الشبه الكروية

Studies of cell-cell cohesion and cell-substratum adhesion have historically been performed on monolayer cultures adherent to rigid substrates. Cells ...

Cellular Lipid Extraction for Targeted Stable Isotope Dilution Liquid Chromatography-Mass Spectrometry Analysis

The metabolism of fatty acids, such as arachidonic acid (AA) and linoleic acid (LA), results in the formation of oxidized bioactive lipids, including numerous stereoisomers1,2. These metabolites can be formed from free or esterified fatty acids. Many of these oxidized metabolites have biological activity and have been implicated in various diseases including cardiovascular and neurodegenerative diseases, asthma, and cancer3-7. Oxidized bioactive lipids can be formed enzymatically or by reactive oxygen species (ROS). Enzymes that metabolize fatty acids include cyclooxygenase (COX), lipoxygenase (LO), and cytochromes P450 (CYPs)1,8. Enzymatic metabolism results in enantioselective formation whereas ROS oxidation results in the racemic formation of products.
While this protocol focuses primarily on the analysis of AA- and some LA-derived bioactive metabolites; it could be easily applied to metabolites of other fatty acids. Bioactive lipids are extracted from cell lysate or media using liquid-liquid (l-l) extraction. At the beginning of the l-l extraction process, stable isotope internal standards are added to account for errors during sample preparation. Stable isotope dilution (SID) also accounts for any differences, such as ion suppression, that metabolites may experience during the mass spectrometry (MS) analysis9. After the extraction, derivatization with an electron capture (EC) reagent, pentafluorylbenzyl bromide (PFB) is employed to increase detection sensitivity10,11. Multiple reaction monitoring (MRM) is used to increase the selectivity of the MS analysis. Before MS analysis, lipids are separated using chiral normal phase high performance liquid chromatography (HPLC). The HPLC conditions are optimized to separate the enantiomers and various stereoisomers of the monitored lipids12. This specific LC-MS method monitors prostaglandins (PGs), isoprostanes (isoPs), hydroxyeicosatetraenoic acids (HETEs), hydroxyoctadecadienoic acids (HODEs), oxoeicosatetraenoic acids (oxoETEs) and oxooctadecadienoic acids (oxoODEs); however, the HPLC and MS parameters can be optimized to include any fatty acid metabolites13.
Most of the currently available bioanalytical methods do not take into account the separate quantification of enantiomers. This is extremely important when trying to deduce whether or not the metabolites were formed enzymatically or by ROS. Additionally, the ratios of the enantiomers may provide evidence for a specific enzymatic pathway of formation. The use of SID allows for accurate quantification of metabolites and accounts for any sample loss during preparation as well as the differences experienced during ionization. Using the PFB electron capture reagent increases the sensitivity of detection by two orders of magnitude over conventional APCI methods. Overall, this method, SID-LC-EC-atmospheric pressure chemical ionization APCI-MRM/MS, is one of the most sensitive, selective, and accurate methods of quantification for bioactive lipids.

This protocol will demonstrate the extraction and analysis of free and esterified bioactive fatty acids from cells. Fatty acids are accurately quantified using stable isotope dilution, chiral liquid chromatography, electron capture atmospheric chemical ionization multiple reaction monitoring mass spectrometry (SID-LC-ECAPCI-MRM/MS).

الخلوية لاستخراج الدهن المستهدفة التخفيف النظائر المستقرة تحليل السائل الطيف اللوني القداس

The metabolism of fatty acids, such as arachidonic acid (AA) and linoleic acid (LA), results in the formation of oxidized bioactive lipids, including ...

Wide-field Fluorescent Microscopy and Fluorescent Imaging Flow Cytometry on a Cell-phone

Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general relatively bulky and costly, making them less effective in the resource limited settings. To potentially address these limitations, we have recently demonstrated the integration of wide-field fluorescent microscopy and imaging flow cytometry tools on cell-phones using compact, light-weight, and cost-effective opto-fluidic attachments. In our flow cytometry design, fluorescently labeled cells are flushed through a microfluidic channel that is positioned above the existing cell-phone camera unit. Battery powered light-emitting diodes (LEDs) are butt-coupled to the side of this microfluidic chip, which effectively acts as a multi-mode slab waveguide, where the excitation light is guided to uniformly excite the fluorescent targets. The cell-phone camera records a time lapse movie of the fluorescent cells flowing through the microfluidic channel, where the digital frames of this movie are processed to count the number of the labeled cells within the target solution of interest. Using a similar opto-fluidic design, we can also image these fluorescently labeled cells in static mode by e.g. sandwiching the fluorescent particles between two glass slides and capturing their fluorescent images using the cell-phone camera, which can achieve a spatial resolution of e.g. ~ 10 &mu;m over a very large field-of-view of ~ 81 mm2. This cell-phone based fluorescent imaging flow cytometry and microscopy platform might be useful especially in resource limited settings, for e.g. counting of CD4+ T cells toward monitoring of HIV+ patients or for detection of water-borne parasites in drinking water.

We review our recent results on the integration of fluorescent microscopy and imaging flow cytometry tools on a cell-phone using compact and cost-effective opto-fluidic attachments. These cell-phone based micro-analysis devices might be useful for cytometric analysis, such as performing various cell counting tasks as well as for high-throughput screening of e.g., water samples in resource limited settings.

واسعة المجال المجهري نيون نيون قياس التدفق الخلوي والتصوير على الهاتف الخلوي

Fluorescent microscopy and flow cytometry are widely used tools in biomedical research and clinical diagnosis. However these devices are in general ...

Imaging of Biological Tissues by Desorption Electrospray Ionization Mass Spectrometry

Mass spectrometry imaging (MSI) provides untargeted molecular information with the highest specificity and spatial resolution for investigating biological tissues at the hundreds to tens of microns scale. When performed under ambient conditions, sample pre-treatment becomes unnecessary, thus simplifying the protocol while maintaining the high quality of information obtained. Desorption electrospray ionization (DESI) is a spray-based ambient MSI technique that allows for the direct sampling of surfaces in the open air, even in vivo. When used with a software-controlled sample stage, the sample is rastered underneath the DESI ionization probe, and through the time domain, m/z information is correlated with the chemical species' spatial distribution. The fidelity of the DESI-MSI output depends on the source orientation and positioning with respect to the sample surface and mass spectrometer inlet. Herein, we review how to prepare tissue sections for DESI imaging and additional experimental conditions that directly affect image quality. Specifically, we describe the protocol for the imaging of rat brain tissue sections by DESI-MSI.

Desorption electrospray ionization mass spectrometry (DESI-MS) is an ambient method by which samples, including biological tissues, can be imaged with minimal sample preparation. By rastering the sample below the ionization probe, this spray-based technique provides sufficient spatial resolution to discern molecular features of interest within tissue sections.

التصوير من الأنسجة البيولوجية بواسطة الامتزاز Electrospray التأين الطيف الكتلي

Mass spectrometry imaging (MSI) provides untargeted molecular information with the highest specificity and spatial resolution for investigating biological ...

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain central aspects of cellular physiology. To easily combine cell patterning with Multi-Electrode Arrays (MEAs) and silicon-based &#8216;lab on a chip&#8217; technologies, a microfabrication-compatible protocol is required. We describe a method that utilizes deposition of the polymer parylene-C on SiO2&#160;wafers. Photolithography enables accurate and reliable patterning of parylene-C at micron-level resolution. Subsequent activation by immersion in fetal bovine serum (or another specific activation solution) results in a substrate in which cultured cells adhere to, or are repulsed by, parylene or SiO2 regions respectively. This technique has allowed patterning of a broad range of cell types (including primary murine hippocampal cells, HEK 293 cell line, human neuron-like teratocarcinoma cell line, primary murine cerebellar granule cells, and primary human glioma-derived stem-like cells). Interestingly, however, the platform is not universal; reflecting the importance of cell-specific adhesion molecules. This cell patterning process is cost effective, reliable, and importantly can be incorporated into standard microfabrication (chip manufacturing) protocols, paving the way for integration of microelectronic technology.

Cell Patterning on Photolithographically Defined 
Parylene-C: SiO2 Substrates

This protocol describes a microfabrication-compatible method for cell patterning on SiO2. A predefined parylene-C design is photolithographically printed on SiO2 wafers. Following incubation with serum (or other activation solution) cells adhere specifically to (and grow according to the conformity of) underlying parylene-C, whilst being repulsed by SiO2 regions.

الزخرفة الخلية على Photolithographically معرفة Parylene-C: شافي<sub&gt; 2</sub&gt; ركائز

Cell patterning platforms support broad research goals, such as construction of predefined in vitro neuronal networks and the exploration of certain ...

Sample Preparation Strategies for Mass Spectrometry Imaging of 3D Cell Culture Models

Three dimensional cell cultures are attractive models for biological research. They combine the flexibility and cost-effectiveness of cell culture with some of the spatial and molecular complexity of tissue. For example, many cell lines form 3D structures given appropriate in vitro conditions. Colon cancer cell lines form 3D cell culture spheroids, in vitro mimics of avascular tumor nodules. While immunohistochemistry and other classical imaging methods are popular for monitoring the distribution of specific analytes, mass spectrometric imaging examines the distribution of classes of molecules in an unbiased fashion. While MALDI mass spectrometric imaging was originally developed to interrogate samples obtained from humans or animal models, this report describes the analysis of in vitro three dimensional cell cultures, including improvements in sample preparation strategies. Herein is described methods for growth, harvesting, sectioning, washing, and analysis of 3D cell cultures via matrix-assisted laser desorption/ionization-mass spectrometry (MALDI-MS) imaging. Using colon carcinoma 3D cell cultures as a model system, this protocol demonstrates the ability to monitor analytes in an unbiased fashion across the 3D cell culture system with MALDI-MSI.

Immortalized cancer cell lines can be grown as 3D cell cultures, a valuable model for biological research. This protocol describes mass spectrometry imaging of 3D cell cultures, including improvements in the sample preparation platform. The goal of this protocol is to instruct users to prepare 3D cell cultures for mass spectrometry imaging analysis.

عينة استراتيجيات التحضير للتصوير الطيف الكتلي لل3D الثقافة خلية نماذج

Three dimensional cell cultures are attractive models for biological research. They combine the flexibility and cost-effectiveness of cell culture with ...

Isolation of Primary Human Colon Tumor Cells from Surgical Tissues and Culturing Them Directly on Soft Elastic Substrates for Traction Cytometry

Cancer cells respond to matrix mechanical stiffness in a complex manner using a coordinated, hierarchical mechano-chemical system composed of adhesion receptors and associated signal transduction membrane proteins, the cytoskeletal architecture, and molecular motors1, 2. Mechanosensitivity of different cancer cells in vitro are investigated primarily with immortalized cell lines or murine derived primary cells, not with primary human cancer cells. Hence, little is known about the mechanosensitivity of primary human colon cancer cells in vitro. Here, an optimized protocol is developed that describes the isolation of primary human colon cells from healthy and cancerous surgical human tissue samples. Isolated colon cells are then successfully cultured on soft (2 kPa stiffness) and stiff (10 kPa stiffness) polyacrylamide hydrogels and rigid polystyrene (~3.6 GPa stiffness) substrates functionalized by an extracellular matrix (fibronectin in this case). Fluorescent microbeads are embedded in soft gels near the cell culture surface, and traction assay is performed to assess cellular contractile stresses using free open access software. In addition, immunofluorescence microscopy on different stiffness substrates provides useful information about primary cell morphology, cytoskeleton organization and vinculin containing focal adhesions as a function of substrate rigidity.

A protocol is described to extract primary human cells from surgical colon tumor and normal tissues. The isolated cells are then cultured on soft elastic substrates (polyacrylamide hydrogels) functionalized by an extracellular matrix protein, and embedded with fluorescent microbeads. Traction cytometry is performed to assess cellular contractile stresses.

عزل خلايا ورم القولون الإنسان الأساسية من الأنسجة الجراحية وزراعة بشكل مباشر على لينة مرنة ركائز للالجر الخلوي

Cancer cells respond to matrix mechanical stiffness in a complex manner using a coordinated, hierarchical mechano-chemical system composed of adhesion ...

A Protocol for Bioinspired Design: A Ground Sampler Based on Sea Urchin Jaws

Bioinspired design is an emerging field that takes inspiration from nature to develop high-performance materials and devices. The sea urchin mouthpiece, known as the Aristotle's lantern, is a compelling source of bioinspiration with an intricate network of musculature and calcareous teeth that can scrape, cut, chew food and bore holes into rocky substrates. We describe the bioinspiration process as including animal observation, specimen characterization, device fabrication and mechanism bioexploration. The last step of bioexploration allows for a deeper understanding of the initial biology. The design architecture of the Aristotle's lantern is analyzed with micro-computed tomography and individual teeth are examined with scanning electron microscopy to identify the microstructure. Bioinspired designs are fabricated with a 3D printer, assembled and tested to determine the most efficient lantern opening and closing mechanism. Teeth from the bioinspired lantern design are bioexplored via finite element analysis to explain from a mechanical perspective why keeled tooth structures evolved in the modern sea urchins we observed. This circular approach allows for new conclusions to be drawn from biology and nature.

A protocol for bioinspired design is described for a sampling device based on the jaws of a sea urchin. The bioinspiration process includes observing the sea urchins, characterizing the mouthpiece, 3D printing of the teeth and their assembly, and bioexploring the tooth structure.

بروتوكول لتصميم Bioinspired: أخذ العينات الجوفية بناء على قنفذ البحر الفك المفترس

Bioinspired design is an emerging field that takes inspiration from nature to develop high-performance materials and devices. The sea urchin mouthpiece, ...

Whole-body Mass Spectrometry Imaging by Infrared Matrix-assisted Laser Desorption Electrospray Ionization (IR-MALDESI)

Ambient ionization sources for mass spectrometry (MS) have been the subject of much interest in the past decade. Matrix-assisted laser desorption electrospray ionization (MALDESI) is an example of such methods, where features of matrix-assisted laser desorption/ionization (MALDI) (e.g., pulsed nature of desorption) and electrospray ionization (ESI) (e.g., soft-ionization) are combined. One of the major advantages of MALDESI is its inherent versatility. In MALDESI experiments, an ultraviolet (UV) or infrared (IR) laser can be used to resonantly excite an endogenous or exogenous matrix. The choice of matrix is not analyte dependent, and depends solely on the laser wavelength used for excitation. In IR-MALDESI experiments, a thin layer of ice is deposited on the sample surface as an energy-absorbing matrix. The IR-MALDESI source geometry has been optimized using statistical design of experiments (DOE) for analysis of liquid samples as well as biological tissue specimens. Furthermore, a robust IR-MALDESI imaging source has been developed, where a tunable mid-IR laser is synchronized with a computer controlled XY translational stage and a high resolving power mass spectrometer. A custom graphical user interface (GUI) allows user selection of the repetition rate of the laser, number of shots per voxel, step-size of the sample stage, and the delay between the desorption and scan events for the source. IR-MALDESI has been used in variety of applications such as forensic analysis of fibers and dyes and MSI of biological tissue sections. Distribution of different analytes ranging from endogenous metabolites to exogenous xenobiotics within tissue sections can be measured and quantified using this technique. The protocol presented in this manuscript describes major steps necessary for IR-MALDESI MSI of whole-body tissue sections.

Whole-body Mass Spectrometry Imaging by Infrared Matrix-assisted Laser Desorption Electrospray Ionization IR-MALDESI

A mass spectrometry imaging (MSI) source operated at atmospheric pressure was developed by coupling mid-infrared laser desorption and electrospray post-ionization. Exogenous ice matrix was used as the energy-absorbing matrix to facilitate resonant desorption of tissue-related material. This manuscript provides a step-by-step protocol for performing IR-MALDESI MSI of whole-body neonatal mouse.

كامل الجسم الطيف الكتلي التصوير من قبل بمساعدة مصفوفة الأشعة تحت الحمراء ليزر الامتزاز Electrospray التأين (IR-MALDESI)

Ambient ionization sources for mass spectrometry (MS) have been the subject of much interest in the past decade. Matrix-assisted laser desorption ...

Simultaneous Quantification of Selected Kynurenines Analyzed by Liquid Chromatography-Mass Spectrometry in Medium Collected from Cancer Cell Cultures

The kynurenine pathway and the tryptophan catabolites called kynurenines have received increased attention for their involvement in immune regulation and cancer biology. An in vitro cell culture assay is often used to learn about the contribution of different tryptophan catabolites in a disease mechanism and for testing therapeutic strategies. Cell culture medium that is rich in secreted metabolites and signaling molecules reflects the status of tryptophan metabolism and other cellular events. New protocols for the reliable quantification of multiple kynurenines in the complex cell culture medium are desired to allow for a reliable and quick analysis of multiple samples. This can be accomplished with liquid chromatography coupled with mass spectrometry. This powerful technique is employed in many clinical and research laboratories for the quantification of metabolites and can be used for measuring kynurenines.
Presented here is the use of liquid chromatography coupled with single quadrupole mass spectrometry (LC-SQ) for the simultaneous determination of four kynurenines, i.e., kynurenine, 3-hydroxykynurenine, 3-hydroxyanthranilic, and xanthurenic acid in the medium collected from in vitro cultured cancer cells. SQ detector is simple to use and less expensive compared to other mass spectrometers. In the SQ-MS analysis, multiple ions from the sample are generated and separated according to their specific mass-to-charge ratio (m/z), followed by the detection using a Single Ion Monitoring (SIM) mode.
This paper draws the attention on the advantages of the reported method and indicates some weak points. It is focused on critical elements of LC-SQ analysis including sample preparation along with chromatography and mass spectrometry analysis. The quality control, method calibration conditions and matrix effect issues are also discussed. We described a simple application of 3-nitrotyrosine as one analog standard for all target analytes. As confirmed by experiments with human ovary and breast cancer cells, the proposed LC-SQ method&#160;generates reliable results and can be further applied to other in vitro cellular models.

Described here is a protocol for the determination of four different tryptophan metabolites generated in the kynurenine pathway (kynurenine, 3-hydroxykynurenine, xanthurenic acid, 3-hydroxyanthranilic acid) in the medium collected from cancer cell cultures analyzed by liquid chromatography coupled with a single quadrupole mass spectrometry.

القياس الكمي المتزامن لـ Kynurenines المختارة التي تم تحليلها بواسطة الكروماتوغرافيا السائلة- القياس الطيفي الكتلي في المتوسط الذي تم جمعه من ثقافات الخلايا السرطانية

The kynurenine pathway and the tryptophan catabolites called kynurenines have received increased attention for their involvement in immune regulation and ...