Quick and easy colorimetric test for calibration control of liquid handling workstations

2009 ◽  
Vol 47 (11) ◽  
Author(s):  
Hélène Jeulin ◽  
Odette Agulles ◽  
Bernard Fortier ◽  
Véronique Venard
Keyword(s):  
Liquid Handling ◽  
Colorimetric Test ◽  
Calibration Control

Antibody Screening Results for Anti-Nucleocapsid Antibodies Towards the Development of a SARS-CoV-2 Nucleocapsid Protein Antigen Detecting Lateral Flow Assay

2021 ◽  
Author(s):  
David Cate ◽  
Helen Hsieh ◽  
Veronika Glukhova ◽  
Joshua D Bishop ◽  
H Gleda Hermansky ◽  
...  
Keyword(s):  
Nucleocapsid Protein ◽  
Point Of Care ◽  
Lateral Flow ◽  
Screening Methods ◽  
Antibody Screening ◽  
Liquid Handling ◽  
Large Numbers ◽  
Accurate Performance ◽  
Further Development ◽  
Assay Conditions

<p></p><p>The global COVID-19 pandemic has created an urgent demand for large numbers of inexpensive, accurate, rapid, point-of-care diagnostic tests. Analyte-based assays are suitably inexpensive and can be rapidly mass-produced, but for sufficiently accurate performance they require highly optimized antibodies and assay conditions. We used an automated liquid handling system, customized to handle arrays of lateral flow immunoassay (LFA) tests in a high-throughput screen, to identify anti-nucleocapsid antibodies that will perform optimally in an LFA. We tested 1021 anti-nucleocapsid antibody pairs as LFA capture and detection reagents with the goal of highlighting pairs that have the greatest affinity for unique epitopes of the nucleocapsid protein of SARS-CoV-2 within the LFA format. In contrast to traditional antibody screening methods (e.g., ELISA, bio-layer interferometry), the method described here integrates real-time reaction kinetics with transport in, and immobilization directly onto, nitrocellulose. We have identified several candidate antibody pairs that are suitable for further development of an LFA for SARS-CoV-2.</p><p></p>

scholarly journals A fully automated pipeline for the dynamic at‐line morphology analysis of microscale Aspergillus cultivation

2021 ◽  
Vol 8 (1) ◽  
Author(s):  
Roman Jansen ◽  
Kira Küsters ◽  
Holger Morschett ◽  
Wolfgang Wiechert ◽  
Marco Oldiges
Keyword(s):  
Filamentous Fungi ◽  
High Throughput ◽  
Automated Image Analysis ◽  
Height Velocity ◽  
Pellet Size ◽  
Application Study ◽  
Liquid Handling ◽  
Morphology Analysis ◽  
Development And Utilization ◽  
Increasing Demand

Abstract Background Morphology, being one of the key factors influencing productivity of filamentous fungi, is of great interest during bioprocess development. With increasing demand of high-throughput phenotyping technologies for fungi due to the emergence of novel time-efficient genetic engineering technologies, workflows for automated liquid handling combined with high-throughput morphology analysis have to be developed. Results In this study, a protocol allowing for 48 parallel microbioreactor cultivations of Aspergillus carbonarius with non-invasive online signals of backscatter and dissolved oxygen was established. To handle the increased cultivation throughput, the utilized microbioreactor is integrated into a liquid handling platform. During cultivation of filamentous fungi, cell suspensions result in either viscous broths or form pellets with varying size throughout the process. Therefore, tailor-made liquid handling parameters such as aspiration/dispense height, velocity and mixing steps were optimized and validated. Development and utilization of a novel injection station enabled a workflow, where biomass samples are automatically transferred into a flow through chamber fixed under a light microscope. In combination with an automated image analysis concept, this enabled an automated morphology analysis pipeline. The workflow was tested in a first application study, where the projected biomass area was determined at two different cultivation temperatures and compared to the microbioreactor online signals. Conclusions A novel and robust workflow starting from microbioreactor cultivation, automated sample harvest and processing via liquid handling robots up to automated morphology analysis was developed. This protocol enables the determination of projected biomass areas for filamentous fungi in an automated and high-throughput manner. This measurement of morphology can be applied to describe overall pellet size distribution and heterogeneity.

scholarly journals The use of ortho-tolidine as a colorimetric test for gold

The Analyst ◽  
1919 ◽  
Vol 44 (516) ◽  
pp. 94 ◽  
Author(s):  
W. B. Pollard
Keyword(s):  
Colorimetric Test

scholarly journals A Smartphone Camera Colorimetric Assay of Acetylcholinesterase and Butyrylcholinesterase Activity

Sensors ◽  
2021 ◽  
Vol 21 (5) ◽  
pp. 1796
Author(s):  
Miroslav Pohanka ◽  
Jitka Zakova
Keyword(s):  
Limit Of Detection ◽  
Colorimetric Assay ◽  
Point Of Care ◽  
Specific Treatment ◽  
Point Of Care Testing ◽  
Analytical Instruments ◽  
Colorimetric Test ◽  
3D Printed ◽  
Butyrylcholinesterase Activity ◽  
Additional Education

Acetylcholinesterase (AChE) and butyrylcholinesterase (BChE) can serve as biochemical markers of various pathologies like liver disfunction and poisonings by nerve agents. Ellman’s assay is the standard spectrophotometric method to measure cholinesterase activity in clinical laboratories. The authors present a new colorimetric test to assess AChE and BChE activity in biological samples using chromogenic reagents, treated 3D-printed measuring pads and a smartphone camera as a signal detector. Multiwell pads treated with reagent substrates 2,6-dichlorophenolindophenyl acetate, indoxylacetate, ethoxyresorufin and methoxyresorufin were prepared and tested for AChE and BChE. In the experiments, 3D-printed pads containing indoxylacetate as a chromogenic substrate were optimal for analytical purposes. The best results were achieved using the red (R) channel, where the limit of detection was 4.05 µkat/mL for BChE and 4.38 µkat/mL for AChE using a 40 µL sample and a 60 min assay. The major advantage of this method is its overall simplicity, as samples are applied directly without any specific treatment or added reagents. The assay was also validated to the standard Ellman’s assay using human plasma samples. In conclusion, this smartphone camera-based colorimetric assay appears to have practical applicability and to be a suitable method for point-of-care testing because it does not require specific manipulation, additional education of staff or use of sophisticated analytical instruments.

Use of a crystallization robot to set up sitting-drop vapor-diffusion crystallization andin situcrystallization screens

2000 ◽  
Vol 33 (2) ◽  
pp. 344-349 ◽  
Author(s):  
Christopher F. Snook ◽  
Michael D. Purdy ◽  
Michael C. Wiener
Keyword(s):  
Membrane Proteins ◽  
Protein Crystallization ◽  
Integral Membrane Proteins ◽  
Vapor Diffusion ◽  
Liquid Handling ◽  
General Utility ◽  
Crystallization Experiments ◽  
Automated Screening ◽  
Set Up

A commercial crystallization robot has been modified for use in setting up sitting-drop vapor-diffusion crystallization experiments, and for setting up protein crystallization screensin situ. The primary aim of this effort is the automated screening of crystallization of integral membrane proteins in detergent-containing solutions. However, the results of this work are of general utility to robotic liquid-handling systems. Sources of error that can prevent the accurate dispensing and mixing of solutions have been identified, and include local environmental, machine-specific and solution conditions. Solutions to each of these problems have been developed and implemented.

scholarly journals Organoid technology for personalized pancreatic cancer therapy

2021 ◽  
Author(s):  
Axel Bengtsson ◽  
Roland Andersson ◽  
Jonas Rahm ◽  
Karthik Ganganna ◽  
Bodil Andersson ◽  
...  
Keyword(s):  
Drug Screening ◽  
Response Prediction ◽  
Metabolic Imaging ◽  
Ductal Adenocarcinoma ◽  
3D Bioprinting ◽  
Preclinical Models ◽  
Liquid Handling ◽  
Technical Solutions ◽  
Pancreatic Cancer Therapy ◽  
Related Mortality

Abstract Background Pancreatic ductal adenocarcinoma has the lowest survival rate among all major cancers and is the third leading cause of cancer-related mortality. The stagnant survival statistics and dismal response rates to current therapeutics highlight the need for more efficient preclinical models. Patient-derived organoids (PDOs) offer new possibilities as powerful preclinical models able to account for interpatient variability. Organoid development can be divided into four different key phases: establishment, propagation, drug screening and response prediction. Establishment entails tailored tissue extraction and growth protocols, propagation requires consistent multiplication and passaging, while drug screening and response prediction will benefit from shorter and more precise assays, and clear decision-making tools. Conclusions This review attempts to outline the most important challenges that remain in exploiting organoid platforms for drug discovery and clinical applications. Some of these challenges may be overcome by novel methods that are under investigation, such as 3D bioprinting systems, microfluidic systems, optical metabolic imaging and liquid handling robotics. We also propose an optimized organoid workflow inspired by all technical solutions we have presented.

scholarly journals A 384-HTS for Human Factor VIIa: Comparison With 96- and 864-Well Formats

1997 ◽  
Vol 2 (3) ◽  
pp. 171-178 ◽  
Author(s):  
John C.W. Comley ◽  
Alastair Binnie ◽  
Caroline Bonk ◽  
John G. Houston
Keyword(s):  
Tissue Factor ◽  
Dose Response ◽  
Human Factor ◽  
Factor Viia ◽  
Assay Development ◽  
Fluorescent Detection ◽  
Response Curves ◽  
Liquid Handling ◽  
Dose Response Curves ◽  
Assay Volume

A homogenous fluorescent HTS for recombinant human factor VIIa (FVIIa) using soluble tissue factor has been developed in 384-well microplates. In this report we discuss our experiences with assay development, liquid handling using a Tomtec Quadra and Matrix PlateMate, fluorescent detection and screening of -200,000 compounds against FVIIa in 384-well plate format. Assays using the entire Helix 864-well plate were prototyped using contact dispensing with a modified Hamilton Microlab 2200. FVIIa was used as a model assay to compare between 96-, 384-, and 864-plate formats in a total assay volume of 100, 25, and 10 μl, respectively. FVIIa was assayed in 864 to the same degree of sensitivity as 384- and 96-well assays and dose-response curves for a standard inhibitor (benzamidine) in the FVIIa assay were identical in all plate formats. Finally, we review the prospects for HTS in 864-well microplates.

New Colorimetric Test for Rapid Diagnosis of Streptococcal Pharyngitis: A Warning

PEDIATRICS ◽  
1990 ◽  
Vol 86 (3) ◽  
pp. 457-459
Author(s):  
Michael A. Gerber ◽  
Richard R. Facklam ◽  
Martin F. Randolph ◽  
Kathleen K. DeMeo
Keyword(s):  
Drug Administration ◽  
Diagnostic Tests ◽  
Streptococcal Pharyngitis ◽  
Rapid Diagnosis ◽  
Group A Streptococci ◽  
Pharmacologic Agent ◽  
The Past ◽  
Colorimetric Test ◽  
Group A ◽  
Rapid Tests

During the last few years there has been a dramatic proliferation of rapid tests for the diagnosis of group A β-hemolytic streptococcal pharyngitis.1 It is important for physicians to realize that the Food and Drug Administration does not approve these diagnostic tests as it would approve a pharmacologic agent, but simply permits a manufacturer to sell the test. Consequently, unacceptably inaccurate rapid tests for group A streptococci have been marketed in the past and could potentially appear again at anytime. In 1986, we studied a new enzyme fluorescence procedure (Strep-A-Fluor, Bio-Spec Inc, Dublin, CA) for the rapid diagnosis of group A β-hemolytic streptococcal pharyngitis.2

Sign in / Sign up

Export Citation Format

Share Document