Robotic Liquid Handling Research Articles

Automation of Biochemical Assays Using an Open-sourced, Inexpensive Robotic Liquid Handler.

High Throughput Screening is crucial in pharmaceutical companies for efficient testing in drug discovery and development. Our Vaccines Analytical Research and Development Department (V-AR&D) extensively uses Robotic Liquid Handlers in their High Throughput Analytics (HTA) group for assay development and sample screening. However, these instruments are expensive and require extensive training. Opentrons' OT-2 liquid handler offers a more affordable option (< $10,000) with Python programming language and open-source flexibility, reducing training requirements. OT-2 allows broadening of testing capabilities and method transfer without significant capital investments. Two biochemical assays were conducted to assess OT-2′s performance, and it demonstrated accurate pipetting with low covariance compared to Tecan-EVO liquid handlers. Though OT-2 has some limitations such as lack of a crash detection system and limited deck space, it is a cost-effective, medium-throughput, and accurate liquid handling tool suitable for early-stage development and method transfer.

Development of an Automated, Ultra-Rapid Bottom-Up Proteomics Workflow Utilizing Alginate-Based Hydrogels.

A new approach to sample preparation and enzymatic digestion in bottom-up proteomics has been developed using alginate-based hydrogel entrapment of enzymes. This hydrogel facilitates rapid and room-temperature digestions with multienzyme capabilities. Three methodologies were tested: within microcentrifuge tubes, in situ pipette tips, and automated robotic liquid handling. Factorial experimental design identified a 1 h, room temperature, pepsin-trypsin dual-enzyme digestion as optimal for sequence coverage and protein group identification, comparable to a gold-standard overnight proteomic protocol. This method promises significant advancements in proteomic analysis by enhancing reusability, speed, throughput, convenience, and cost-effectiveness, without hindering digestion efficiency.

Assay Development for High-Throughput Drug Screening Against Mycobacteria.

Mycobacterium abscessus (Mab) infections are challenging to treat due to high intrinsic drug resistance, comparable to multidrug-resistant tuberculosis. Treatments are extremely ineffective and based on a multi-drug regimen, resulting in low patient compliance. Consequently, the scientific community is urged to identify new and effective drugs to treat these infections. One of the strategies employed to this end is drug repurposing - the process of identifying new therapeutic opportunities for existing drugs in the market, circumventing the time required to establish pharmacokinetic and safety profiles of new drugs. With most studies on drug development against Mab relying on traditional and time-consuming methods, an assay for high-throughput drug screening was developed against mycobacteria using an in house developed double-reporter strain of Mab. Using liquid-handling robotics, automated microscopy, and analysis, alongside in house developed double reporter strains, bacterial viability can be rapidly measured using two different readouts, luminescence and fluorescence, without adding reagents or performing any extra steps. This reduces time and variability between assays, a major advantage for high-throughput screenings. The described protocol was validated by screening a library of 1280 compounds. The obtained results were corroborated by the literature, with efficient detection of active compounds. Thus, this work fulfilled the aim of supplying the field with a new tool to help fight this extremely drug-resistant bacteria.

Identification of inhibitors of human ChaC1, a cytoplasmic glutathione degrading enzyme through high throughput screens in yeast.

The cytosolic glutathione-degrading enzyme, ChaC1, is highly up-regulated in several cancers, with the up-regulation correlating to poor prognosis. The ability to inhibit ChaC1 is therefore important in different pathophysiological situations, but is challenging owing to the high substrate Km of the enzyme. As no inhibitors of ChaC1 are known, in this study we have focussed on this goal. We have initially taken a computational approach where a systemic structure-based virtual screening was performed. However, none of the predicted hits proved to be effective inhibitors. Synthetic substrate analogs were also not inhibitory. As both these approaches targeted the active site, we shifted to developing two high-throughput, robust, yeast-based assays that were active site independent. A small molecule compound library was screened using an automated liquid handling system using these screens. The hits were further analyzed using in vitro assays. Among them, juglone, a naturally occurring naphthoquinone, completely inhibited ChaC1 activity with an IC50 of 8.7 µM. It was also effective against the ChaC2 enzyme. Kinetic studies indicated that the inhibition was not competitive with the substrate. Juglone is known to form adducts with glutathione and is also known to selectively inhibit enzymes by covalently binding to active site cysteine residues. However, juglone continued to inhibit a cysteine-free ChaC1 variant, indicating that it was acting through a novel mechanism. We evaluated different inhibitory mechanisms, and also analogues of juglone, and found plumbagin effective as an inhibitor. These compounds are the first inhibitor leads against the ChaC enzymes using a robust yeast screen.

Development of a Versatile High-through-put Oligonucleotide LC-MS Method to Accelerate Drug Discovery.

Liquid chromatography-mass spectrometry (LC-MS) is an effective tool for high-throughput quantification of oligonucleotides that is crucial for understanding their biological roles and developing diagnostic tests. This paper presents a high-throughput LC-MS/MS method that may be versatilely applied for a wide range of oligonucleotides, making it a valuable tool for rapid screening and discovery. The method is demonstrated using an in-house synthesized MALAT-1 Antisense oligonucleotide (ASO) as a test case. Biological samples were purified using a reversed liquid-liquid extraction process automated by a liquid handling workstation and analyzed with ion-pairing LC-MS/MS. The assay was evaluated for sensitivity (LLOQ = 2nM), specificity, precision, accuracy, recovery, matrix effect, and stability in rat cerebrospinal fluid (CSF) and plasma. Besides some existing considerations such as column selection, ion-pairing reagent, and sample purification, our work focused on the following four subtopics: 1) selecting the appropriate Multiple Reaction Monitoring (MRM) transition to maximize sensitivity for trace-level ASO in biological samples; 2) utilizing a generic risk-free internal standard (tenofovir) to avoid crosstalk interference from the oligo internal standard commonly utilized in the LC-MS assay; 3) automating the sample preparation process to increase precision and throughput; and 4) comparing liquid-liquid extraction (LLE) and solid-phase extraction (SPE) as sample purification methods in oligo method development. The study quantified the concentration of MALAT-1 ASO in rat CSF and plasma after intrathecal injection and used the difference between the two matrices to evaluate the injection technique. The results provide a solid foundation for further internal oligonucleotide discovery and development.

Liquid Handling Technologies: A Study through Major Discoveries and Advancements

Liquid handling is an essential process in laboratories involving automatically transferring accurate amounts of liquids for various task completions such as sample preparation, pipetting, dilution, and mixing. Automated liquid handling systems (ALHS) help to minimize the errors, complications, and difficulties that are faced with manual methods of liquid handling by efficiently enhancing the accuracy, precision, and reproducibility of experimental workflows and have transformed life sciences aiding research in various fields. Processes like Nuclear Magnetic Resonance (NMR) spectrometry, mass spectrometry, and acoustic droplet ejection with ALHS showcase tremendous potential. Outdated manual machinery is being replaced rapidly with automated tools. We have observed that these laboratory setups are sophisticated and costly. It is challenging to access such technologies, especially in poor or developing countries. At the nanoscale level, handling and evaporation of biomaterials becomes a great issue. Multitudinous devices can combat the cost issue along with utilization of single equipment without the enhancement of add-on modules. Liquid handling devices enhance the quality of experiments contributing to efficient dealing of circumstances like COVID-19. They aid in genomics and proteomics and play a pivotal role in liquid manipulation, drug screening, quantifications, forensic studies and many more. Liquid handling devices with robotic equipment can perform multiple tasks and can assist in a wide range of fields. We anticipate that in the coming years, our laboratories will be furnished with advanced, robotic technologies and cause a revolution in the scientific scenery.

An optimised method to isotopically label pure synthetic peptides 'in-house' for absolute quantification in bottom-up proteomics.

Heavy-labelled internal standards increasingly represent the gold standard for absolute quantitation in mass spectrometry (MS)-based bottom-up proteomics. The biggest drawbacks of using these standards are that they have high costs and lengthy lead times. We describe an efficient, low-cost optimised method to enable 'in-house' heavy labelling of synthetic tryptic peptides for absolute quantification using tandem LC-MS/MS mass spectrometry. Our methodology uses 18O water in a trypsin-catalysed oxygen exchange reaction at the carboxyl terminus with the overall aim of reducing the costs and lead time associated with sourcing heavy standards from commercial vendors. Step-by-step instructions are provided on how to execute this protocol with high-throughput adaptations utilising a 96-well plate and a liquid-handling robot. Detailed notes on experimental setup, tips for troubleshooting and suggested improvements to maximise labelling efficiencies are highlighted to achieve the best results. Under optimum conditions, labelling efficiencies of peptides can reach from 95% to 100%. The application of the 'in-house' labelled standards in generating calibration curves to quantify endogenous peptide concentrations is just as effective as using the synthetically sourced standards while also having great cost reduction implications as well as saving time spent waiting for peptides to arrive. The protocol is highly adaptable and can be customized to fit the specific setup of any laboratory, maximizing achievable labelling efficiencies.

Parallel sample processing for mass spectrometry-based single cell proteomics

BackgroundSingle cell mass spectrometry (scMS) has shown great promise for label free proteomics analysis recently. To present single cell samples for proteomics analysis by MS is not a trivial task. Existing methods rely on robotic liquid handlers to scale up sample preparation throughput. The cost associated with specialized equipment hinders the broad adoption of these workflows, and the sequential sample processing nature limits the ultimate throughput. ResultsIn this work, we report a parallel sample processing workflow that can simultaneously process 10 single cells without the need of robotic liquid handlers for scMS. This method utilized 3D printed microfluidic devices to form reagent arrays on a glass slide, and a magnetic beads-based streamlined sample processing workflow to present peptides for LC-MS detection. We optimized key operational parameters of the method and demonstrated the quantification consistency among 10 parallel processed samples. Finally, the utility of the method in differentiating cell lines and studying the proteome change induced by drug treatment were demonstrated. SignificanceThe present method allows parallel sample processing for single cells without the need of expensive liquid handlers, which has great potential to further improve throughput and decrease the barrier for single cell proteomics.

Evaluation of an automatic sample preparer in the development and validation of an analytical method for vial wall sorptive extraction

Automation has transformed the field of analytical chemistry by enhancing efficiency and precision in laboratory processes. A crucial step in analytical workflows, sample preparation, has traditionally relied on manual techniques, leading to variability and inefficiency. Vial wall sorptive extraction (VWSE) is a promising alternative for automating and enhancing sample preparation in analytical processes. This study aims to evaluate the performance of automated VWSE in the analysis of alkanes (C10-C18) in aqueous phases and to explore its potential use in routine laboratory settings for analyzing contaminants in environmental analysis, quality control, and forensics. VWSE devices were developed and characterized, a chromatographic method was established, and the sample preparation process was automated using an automated liquid handling system. The devices manufactured exhibit the best overall response and low standard deviation. Statistical tests confirm the equivalence of the vials prepared. The developed method achieved good results in analytical validation, a wide linear range with a high coefficient of determination (R2 > 0.90), low limits of detection (0.01–1.02 ng mL−1), and low limits of quantification (0.05–1.05 ng mL−1) were achieved. The parameters repeatability (<26.91 %), recovery (91 to 116 %), and intermediate precision (<22.29 %) also achieved a good analytical performance. The developed automated VWSE method proves effective in quantifying alkanes and meets analytical method validation criteria. This research highlights the potential of automated VWSE for sample preparation in various analytical applications.

A droplet robotic system enabled by electret-induced polarization on droplet

Robotics for scientific research are evolving from grasping macro-scale solid materials to directly actuating micro-scale liquid samples. However, current liquid actuation mechanisms often restrict operable liquid types or compromise the activity of biochemical samples by introducing interfering mediums. Here, we propose a robotic liquid handling system enabled by a novel droplet actuation mechanism, termed electret-induced polarization on droplet (EPD). EPD enables all-liquid actuation in principle and experimentally exhibits generality for actuating various inorganic/organic liquids with relative permittivity ranging from 2.25 to 84.2 and volume from 500 nL to 1 mL. Moreover, EPD is capable of actuating various biochemical samples without compromising their activities, including various body fluids, living cells, and proteins. A robotic system is also coupled with the EPD mechanism to enable full automation. EPD’s high adaptability with liquid types and biochemical samples thus promotes the automation of liquid-based scientific experiments across multiple disciplines.

Enabling high-throughput enzyme discovery and engineering with a low-cost, robot-assisted pipeline

As genomic databases expand and artificial intelligence tools advance, there is a growing demand for efficient characterization of large numbers of proteins. To this end, here we describe a generalizable pipeline for high-throughput protein purification using small-scale expression in E. coli and an affordable liquid-handling robot. This low-cost platform enables the purification of 96 proteins in parallel with minimal waste and is scalable for processing hundreds of proteins weekly per user. We demonstrate the performance of this method with the expression and purification of the leading poly(ethylene terephthalate) hydrolases reported in the literature. Replicate experiments demonstrated reproducibility and enzyme purity and yields (up to 400 µg) sufficient for comprehensive analyses of both thermostability and activity, generating a standardized benchmark dataset for comparing these plastic-degrading enzymes. The cost-effectiveness and ease of implementation of this platform render it broadly applicable to diverse protein characterization challenges in the biological sciences.

Automation of 3D digital rolling circle amplification using a 3D-printed liquid handler

Automation of liquid handling is indispensable to improve throughput and reproducibility in biochemical assays. However, the incorporation of automated systems into laboratory workflows is often hindered by the high cost and complexity associated with building robotic liquid handlers. Here, we report a 3D-printed liquid handler based on a fluidic manifold, thereby obviating the need for complex robotic mechanisms. The fluidic manifold, termed a dispensing and aspirating (DA) device, comprises parallelized multi-pipette structures connected by distribution and aspiration channels, enabling the precise supply and removal of reagents, respectively. Leveraging the versatility of 3D printing, the DA device can be custom-designed and printed to fit specific applications. As a proof-of-principle, we engineered a 3D-printed liquid handler dedicated for 3D digital rolling circle amplification (4DRCA), an advanced biochemical assay involving multiple sample preparation steps such as antibody incubation, cell fixation, nucleic acid amplification, probe hybridization, and extensive washing. We demonstrate the efficacy of the 3D-printed liquid handler to automate the preparation of clinical samples for the simultaneous, in situ analysis of oncogenic protein and transcript markers in B-cell acute lymphoblastic leukemia cells using 4DRCA. This approach provides an effective and accessible solution for liquid handling automation, offering high throughput and reproducibility in biochemical assays.

Development and validation of an automated robotic system for preparation of embryo culture dishes

ObjectiveTo study the development and clinical validation of the ART Pipetting Robot for the IVF Laboratory (APRIL), a liquid-handling robot customized for the precise preparation of microdroplet culture dishes in the field of in vitro fertilization (IVF). DesignA prospective randomized study conducted at an academic IVF center comparing mouse and human embryo outcomes and quantitative measures of accuracy in embryo dishes prepared using APRIL compared with standard manual preparation. SubjectsThe study involved the assessment of the automated culture dish preparation system, APRIL, compared to manual preparation methods in the context of IVF. ExposureAPRIL, an enclosed liquid-handling robot equipped with custom 3D-printed adapters and designed to dispense embryo culture media and mineral oil into microdroplet culture dishes. Main Outcome MeasuresThe study evaluated the precision and consistency of APRIL in culture dish preparation looking at droplet mass, pH of prepared media droplets, and mouse and human embryo development rates. Clinical implementation was assessed by comparing embryo development and outcomes in dishes prepared by APRIL and human embryologists. ResultsCompared with embryo culture dishes prepared using standard manual procedures, embryo culture dishes prepared using APRIL demonstrated a greater than ten-fold improvement in consistence (CV 0.46% vs. 6-7%), maintained optimal pH levels (pH range 7.281-7.33 vs 7.275-7.311), and had a greater mouse embryo blastocyst rate (100% vs 90-91%). Human embryos cultured in dishes prepared by APRIL had a higher rate of development to Day 3 (92.4% vs. 82.6%, p<0.05) and Day 5 (19.75% vs. 15.57%) and a total number of usable embryos (50.3% vs. 46.1%) compared with manually prepared dishes, though the last two outcomes did not reach statistical significance. ConclusionThe results suggest that the use of an automated robotic system for preparation of embryo culture dishes may improve accuracy and outcome measures while reducing the need for trained laboratory personnel to manually prepare the dishes.

Automated ELISA for potency measurements of therapeutic antibodies and antibody fragments

Potency assays are essential for the development and quality control of biopharmaceutical drugs, but they are often a time limiting factor due to manual handling steps and consequently low analytical throughput. On the other hand, automation of potency assays can be challenging due to their complexity and the use of biological materials. ELISA (enzyme-linked immunosorbent assay) is widely used for potency determination and is a good candidate for automation as all ELISA types depend on the same basic steps: coating, blocking, sample incubation, detection, and signal measurement. Nevertheless, ELISA for relative potency measurements still require drug-specific development and assay validation thereby complicating automation efforts. To simplify potency testing by ELISA, we first developed a manual protocol generally applicable to different drugs and then adapted this protocol for automated measurements. We identified unexpected critical parameters which had to be adapted to transfer the manual ELISA to an automated liquid handling system and we demonstrated that gravimetric sample dilution is unnecessary with the automated protocol. Both manual and automated protocols were validated and compared using multiple biotherapeutics. The automated protocol showed similar or higher precision and accuracy when compared to the manual method.

Abstract 3127: Development of three-dimensional cancer cell line spheroid models for the in vitro functional characterization of cytotoxic antibody-drug conjugates

Abstract Background: Antibody-drug conjugates (ADCs) are an effective class of cancer therapeutics which have gained prominence for the treatment of several malignancies. A cytotoxic ADC consists of a linker-payload conjugated to a monoclonal antibody, which targets a distinct tumor-associated antigen (TAA) to enable the delivery of the cytotoxic payload to cancer cells. Presently, there is a need for in vitro models that better recapitulate in vivo tumor tissue complexity to aid in the screening and evaluation of ADCs during preclinical development. Hence, efforts have been made to develop in vitro three-dimensional (3D) models with improved translation to in vivo tumor models compared to traditional two-dimensional (2D) cancer cell line monolayer models. We aimed to generate monoculture cancer cell line spheroids in a high-throughput manner. Subsequently, we sought to evaluate the spheroid penetration capability of structurally distinct ADCs and to assess the 3D cytotoxic activity of a variety of microtubule inhibitor (MTI) and topoisomerase 1 inhibitor (TOPO1i)-bearing ADCs targeting multiple TAAs, comparing to activity in 2D models. Methods: Monoculture cancer cell spheroids were generated by seeding cells from a variety of tumor types, using an automated liquid-handling robot, into microtiter plates treated with ultra-low attachment coating, which allows for scaffold-free self-assembly of cancer cells into a 3D arrangement. Following spheroid formation by incubation for 2-3 days under standard culturing conditions, spheroids were treated with ADCs at a range of concentrations for functional evaluation: the spheroid penetration capability of ADCs of different antibody formats was assessed using high-content confocal imaging of spheroids treated with fluorescently labeled antibodies; the cytotoxic activity of ADCs was characterized using an ATP quantification luminescent reagent, live/dead cell fluorescent stains, and confocal imaging. Results: Monoculture spheroids of varying morphologies were successfully and reproducibly generated with a large panel of &amp;gt;50 cancer cell lines derived from &amp;gt;10 tumor types. Antibodies with different formats demonstrated target-mediated binding and a range of spheroid penetration depths. Additionally, MTI and TOPO1i ADCs evaluated in a panel of cancer cell spheroids demonstrated robust 3D cytotoxicity and differentiated activity when compared to the 2D monolayer assay. In a number of cases, the potency trends across multiple ADCs in 3D cytotoxicity assays were more predictive of in vivo efficacy compared to the 2D assay. Taken together, our high-throughput spheroid assays present important and straightforward in vitro tools to aid in the screening and selection of therapeutic cytotoxic ADC candidates for the treatment of solid tumors. Citation Format: Jodi Wong, Andrea Hernández Rojas, Allysha Bissessur, Lemlem T. Degefie, Araba P. Sagoe-Wagner, Samir Das, Vincent Fung, Kevin Yin, Renee Duan, Sam Lawn, Laurence Madera, Catrina Mi Jung Kim, Alex Wu, Mark E. Petersen, Raffaele Colombo, Jamie R. Rich, Stuart D. Barnscher. Development of three-dimensional cancer cell line spheroid models for the in vitro functional characterization of cytotoxic antibody-drug conjugates [abstract]. In: Proceedings of the American Association for Cancer Research Annual Meeting 2024; Part 1 (Regular Abstracts); 2024 Apr 5-10; San Diego, CA. Philadelphia (PA): AACR; Cancer Res 2024;84(6_Suppl):Abstract nr 3127.

High-Throughput Bacteriophage Testing with Potency Determination: Validation of an Automated Pipetting and Phage Drop-Off Method.

The development of bacteriophages (phages) as active pharmaceutical ingredients for the treatment of patients is on its way and regulatory agencies are calling for reliable methods to assess phage potency. As the number of phage banks is increasing, so is the number of phages that need to be tested to identify therapeutic candidates. Currently, assessment of phage potency on a semi-solid medium to observe plaque-forming units is unavoidable and proves to be labor intensive when considering dozens of phage candidates. Here, we present a method based on automated pipetting and phage drop-off performed by a liquid-handling robot, allowing high-throughput testing and phage potency determination (based on phage titer and efficiency of plaquing). Ten phages were tested, individually and assembled into one cocktail, against 126 Escherichia coli strains. This automated method was compared to the reference one (manual assay) and validated in terms of reproducibility and concordance (ratio of results according to the Bland and Altman method: 0.99; Lin's concordance correlation coefficient: 0.86). We found that coefficients of variation were lower with automated pipetting (mean CV: 13.3% vs. 24.5%). Beyond speeding up the process of phage screening, this method could be used to standardize phage potency evaluation.

Discovery and Characterization of Fluopipamine, a Putative Cellulose Synthase 1 Antagonist within Arabidopsis.

Herbicide-resistant weeds are increasingly a problem in crop fields when exposed to similar chemistry over time. To avoid future yield losses, identifying herbicidal chemistry needs to be accelerated. We screened 50,000 small molecules using a liquid-handling robot and light microscopy focusing on pre-emergent herbicides in the family of cellulose biosynthesis inhibitors. Through phenotypic, chemical, genetic, and in silico methods we uncovered 6-{[4-(2-fluorophenyl)-1-piperazinyl]methyl}-N-(2-methoxy-5-methylphenyl)-1,3,5-triazine-2,4-diamine (fluopipamine). Symptomologies support fluopipamine as a putative antagonist of cellulose synthase enzyme 1 (CESA1) from Arabidopsis (Arabidopsis thaliana). Ectopic lignification, inhibition of etiolation, phenotypes including loss of anisotropic cellular expansion, swollen roots, and live cell imaging link fluopipamine to cellulose biosynthesis inhibition. Radiolabeled glucose incorporation of cellulose decreased in short-duration experiments when seedlings were incubated in fluopipamine. To elucidate the mechanism, ethylmethanesulfonate mutagenized M2 seedlings were screened for fluopipamine resistance. Two loci of genetic resistance were linked to CESA1. In silico docking of fluopipamine, quinoxyphen, and flupoxam against various CESA1 mutations suggests that an alternative binding site at the interface between CESA proteins is necessary to preserve cellulose polymerization in compound presence. These data uncovered potential fundamental mechanisms of cellulose biosynthesis in plants along with feasible leads for herbicidal uses.

Screening and confirmation of psilocin, mitragynine, phencyclidine, ketamine and ketamine metabolites by liquid chromatography-tandem mass spectrometry.

A safe and productive workplace requires a sober workforce, free from substances that impair judgment and concentration. Although drug monitoring programs already exist, the scope and loopholes of standard workplace testing panels are well known, allowing other substances to remain a source of risk. Therefore, a high-throughput urine screening method for psilocin, mitragynine, phencyclidine, ketamine, norketamine and dehydronorketamine was developed and validated in conjunction with a urine and blood confirmation method. There are analytical challenges to overcome with psilocin and mitragynine, particularly when it comes to drug stability and unambiguous identification in authentic specimens. Screening and confirmation methods were validated according to the American National Standards Institute/Academy Standards Board (ANSI/ASB) Standard 036, Standard Practices for Method Validation in Forensic Toxicology. An automated liquid handling system equipped with dispersive pipette extraction tips was utilized for preparing screening samples, whereas an offline solid-phase extraction method was used for confirmation sample preparation. Both methods utilized liquid chromatography-tandem mass spectrometry to achieve limits of detection between 1-5 ng/mL for the screening method and 1 ng/mL for the confirmation method. Automation allows for faster throughput and enhanced quality assurance, which improves turnaround time. Compared to previous in-house methods, specimen volumes were substantially decreased for both blood and urine, which is an advantage when volume is limited. This screening technique is well suited for evaluating large numbers of specimens from those employed in safety-sensitive workforce positions. This method can be utilized by workplace drug testing, human performance and postmortem laboratories seeking robust qualitative screening and confirmation methods for analytes that have traditionally been challenging to routinely analyze.

Optimization of a Hydrogen Exchange-Mass Spectrometry Robotic Liquid Handler Using Tracers.

Hydrogen exchange-mass spectrometry (HX-MS) is a valuable analytical technique that can provide insight into protein interactions and structure. The deuterium labeling necessary to gain this insight is affected by many physical and chemical factors, making it challenging to achieve high reproducibility. Poor precision during dispensing, transfer, and mixing of solutions during the experiment contributes substantially to the overall variability. While the use of a robotic liquid handler can potentially improve precision, its operation must be optimized. We observed poor precision in data collected using a robotic liquid handler to perform HX-MS. In this work, we describe how we were able to improve that system's precision considerably based on tracking performance using caffeine, caffeine-d3, and caffeine-d9 as tracers for the sample, label, and quench to report on each operation of the liquid handling workflow. The insights gained about liquid handler performance and the three-tracer approach can aid in optimizing HX-MS workflow operations, whether performed manually or when using a liquid handling system. Additionally, these tracers can be incorporated as internal tracers during an experiment to report on the labeling and quench operations of each sample throughout the run and, if desired, be used to implement an uptake correction described previously.

AMPERE: automated modular platform for expedited and reproducible electrochemical testing

AMPERE automates sample preparation and electrochemical testing at large scale, enhancing speed, reliability, and openness. It uses a liquid-handling robot with modular reactors to measure metal dissolution for electrochemical stability assessment.