Learning from microarray interlaboratory studies: measures of precision for gene expression

<p>Abstract</p> <p>Background</p> <p>The ability to demonstrate the reproducibility of gene expression microarray results is a critical consideration for the use of microarray technology in clinical applications. While studies have asserted that microarray data can be "highly reproducible" under given conditions, there is little ability to quantitatively compare amongst the various metrics and terminology used to characterize and express measurement performance. Use of standardized conceptual tools can greatly facilitate communication among the user, developer, and regulator stakeholders of the microarray community. While shaped by less highly multiplexed systems, measurement science (metrology) is devoted to establishing a coherent and internationally recognized vocabulary and quantitative practice for the characterization of measurement processes.</p> <p>Results</p> <p>The two independent aspects of the metrological concept of "accuracy" are "trueness" (closeness of a measurement to an accepted reference value) and "precision" (the closeness of measurement results to each other). A carefully designed collaborative study enables estimation of a variety of gene expression measurement precision metrics: repeatability, several flavors of intermediate precision, and reproducibility. The three 2004 Expression Analysis Pilot Proficiency Test collaborative studies, each with 13 to 16 participants, provide triplicate microarray measurements on each of two reference RNA pools. Using and modestly extending the consensus ISO 5725 documentary standard, we evaluate the metrological precision figures of merit for individual microarray signal measurement, building from calculations appropriate to single measurement processes, such as technical replicate expression values for individual probes on a microarray, to the estimation and display of precision functions representing all of the probes in a given platform.</p> <p>Conclusion</p> <p>With only modest extensions, the established metrological framework can be fruitfully used to characterize the measurement performance of microarray and other highly multiplexed systems. Precision functions, summarizing routine precision metrics estimated from appropriately repeated measurements of one or more reference materials as functions of signal level, are demonstrated and merit further development for characterizing measurement platforms, monitoring changes in measurement system performance, and comparing performance among laboratories or analysts.</p

Non Destructive Failure Analysis Technique With a Laboratory Based 3D X-ray Nanotomography System

ABSTRACT X-ray computed tomography (CT) is a powerful nondestructive 3D imaging technique, which enables the visualization of the three dimensional internal structure of opaque materials such as semiconductor devices. Reports of high resolution CT research on life science, materials and semiconductor has mainly been confined to synchrotron radiation centers. This severely limits the availability and accessibility of x-ray microscopes and the wide proliferation of this methodology. We describe a sub-50nm resolution nanoCT system operating at 8 keV in Zernike phase contrast mode based on a commercially available laboratory x-ray source. The system utilizes high-efficiency Fresnel zone plates with an outermost zone width of 35nm resulting in spatial resolution better than 50 nm. The technical description of the system and failure analysis applications notably in visualizing voids, residues in metal interconnects, and competitive analysis in semiconductor devices will be discussed

CCQM key comparison – organic solutions : CCQM-K47 volatile organic compounds in methanol. Final Report

At the October 2005 CCQM Organic Analysis Working Group Meeting (IRMM, Belgium), the decision was made to proceed with a Key Comparison study (CCQM-K47) addressing the calibration function for the determination of volatile organic compounds (VOCs) used for water quality monitoring. This was coordinated by CENAM and NIST. Benzene, o-xylene, m-xylene and p-xylene were chosen as representative VOCs. The solvent of choice was methanol. Key Comparison CCQM-K47 demonstrated the capabilities of participating NMIs to identify and measure the four target VOCs in a calibration solution using GC-based methods. The measurement challenges in CCQM-K47, such as avoiding volatility loss, achieving adequate chromatographic resolution and isolating potential interferences, are typical of those required for value-assigning volatile reference materials. Participants achieving comparable measurements for all four VOCs in this Key Comparison should be capable of providing reference materials and measurements for VOCs in solutions when present at concentration levels greater than 10 µg/g.Fil: Pérez Urquiza, Melina. Centro Nacional de Metrología (CENAM); MéxicoFil: Maldonado Torres, Mauricio. Centro Nacional de Metrología (CENAM); MéxicoFil: Mitani, Yoshito. Centro Nacional de Metrología (CENAM); MéxicoFil: Schantz, Michele M. National Institute of Standards and Technology (NIST); ArgentinaFil: Duewer, David L. National Institute of Standards and Technology (NIST); ArgentinaFil: May, Wille E. National Institute of Standards and Technology (NIST); ArgentinaFil: Parris, Reenie M. National Institute of Standards and Technology (NIST); ArgentinaFil: Wise, Stephen A. National Institute of Standards and Technology (NIST); ArgentinaFil: Kaminski, Katja. Federal Institute for Materials Research and Testing (BAM); AlemaniaFil: Philipp, Rosemarie. Federal Institute for Materials Research and Testing (BAM); AlemaniaFil: Win, Tin. Federal Institute for Materials Research and Testing (BAM); AlemaniaFil: Rosso, Adriana. Instituto Nacional de Tecnología Industrial (INTI); ArgentinaFil: Kim, Dal Ho. Korea Research Institute of Standards and Science (KRISS); Corea del SurFil: Ishikawa, Keiichiro. National Metrology Institute of Japan (NMIJ); JapónFil: Krylov, A. I. D. I. Mendeleev Institute for Metrology (VNIIM); RusiaFil: Kustikov, Y. A. D. I. Mendeleev Institute for Metrology (VNIIM); RusiaFil: Baldan, Annarita. Van Swinden Laboratorium (VS); Países Bajo

Exploring the use of internal and externalcontrols for assessing microarray technical performance

<p>Abstract</p> <p>Background</p> <p>The maturing of gene expression microarray technology and interest in the use of microarray-based applications for clinical and diagnostic applications calls for quantitative measures of quality. This manuscript presents a retrospective study characterizing several approaches to assess technical performance of microarray data measured on the Affymetrix GeneChip platform, including whole-array metrics and information from a standard mixture of external spike-in and endogenous internal controls. Spike-in controls were found to carry the same information about technical performance as whole-array metrics and endogenous "housekeeping" genes. These results support the use of spike-in controls as general tools for performance assessment across time, experimenters and array batches, suggesting that they have potential for comparison of microarray data generated across species using different technologies.</p> <p>Results</p> <p>A layered PCA modeling methodology that uses data from a number of classes of controls (spike-in hybridization, spike-in polyA+, internal RNA degradation, endogenous or "housekeeping genes") was used for the assessment of microarray data quality. The controls provide information on multiple stages of the experimental protocol (e.g., hybridization, RNA amplification). External spike-in, hybridization and RNA labeling controls provide information related to both assay and hybridization performance whereas internal endogenous controls provide quality information on the biological sample. We find that the variance of the data generated from the external and internal controls carries critical information about technical performance; the PCA dissection of this variance is consistent with whole-array quality assessment based on a number of quality assurance/quality control (QA/QC) metrics.</p> <p>Conclusions</p> <p>These results provide support for the use of both external and internal RNA control data to assess the technical quality of microarray experiments. The observed consistency amongst the information carried by internal and external controls and whole-array quality measures offers promise for rationally-designed control standards for routine performance monitoring of multiplexed measurement platforms.</p

CCQM-K55.b (Aldrin) : Final report: october 2012. CCQM-K55.b key comparison on the characterization of organic substances for chemical purity

Under the auspices of the Organic Analysis Working Group (OAWG) of the Comité Consultatif pour la Quantité de Matière (CCQM) a key comparison, CCQM K55.b, was coordinated by the Bureau International des Poids et Mesures (BIPM) in 2010/2011. Nineteen national measurement institutes and the BIPM participated. Participants were required to assign the mass fraction of aldrin present as the main component in the comparison sample for CCQM-K55.b which consisted of technical grade aldrin obtained from the National Measurement Institute Australia that had been subject to serial recrystallization and drying prior to sub-division into the units supplied for the comparison. Aldrin was selected to be representative of the performance of a laboratory's measurement capability for the purity assignment of organic compounds of medium structural complexity [molar mass range 300 Da to 500 Da] and low polarity (pKOW < −2) for which related structure impurities can be quantified by capillary gas phase chromatography (GC). The key comparison reference value (KCRV) for the aldrin content of the material was 950.8 mg/g with a combined standard uncertainty of 0.85 mg/g. The KCRV was assigned by combination of KCRVs assigned by consensus from participant results for each orthogonal impurity class. The relative expanded uncertainties reported by laboratories having results consistent with the KCRV ranged from 0.3% to 0.6% using a mass balance approach and 0.5% to 1% using a qNMR method. The major analytical challenge posed by the material proved to be the detection and quantification of a significant amount of oligomeric organic material within the sample and most participants relying on a mass balance approach displayed a positive bias relative to the KCRV (overestimation of aldrin content) in excess of 10 mg/g due to not having adequate procedures in place to detect and quantify the non-volatile content—specifically the non-volatile organics content—of the comparison sample. There was in general excellent agreement between participants in the identification and the quantification of the total and individual related structure impurities, water content and the residual solvent content of the sample. The comparison demonstrated the utility of 1H NMR as an independent method for quantitative analysis of high purity compounds. In discussion of the participant results it was noted that while several had access to qNMR estimates for the aldrin content that were inconsistent with their mass balance determination they decided to accept the mass balance result and assumed a hidden bias in their NMR data. By contrast, laboratories that placed greater confidence in their qNMR result were able to resolve the discrepancy through additional studies that provided evidence of the presence of non-volatile organic impurity at the requisite level to bring their mass balance and qNMR estimates into agreement.Fil: Westwood, Steven. Bureau International des Poids et Mesures (BIPM); FranciaFil: Josephs, Ralf. Bureau International des Poids et Mesures (BIPM); FranciaFil: Choteau, Tiphaine. Bureau International des Poids et Mesures (BIPM); FranciaFil: Daireaux, Adeline. Bureau International des Poids et Mesures (BIPM); FranciaFil: Mesquida, Charline. Bureau International des Poids et Mesures (BIPM); FranciaFil: Wielgosz, Robert. Bureau International des Poids et Mesures (BIPM); FranciaFil: Rosso, Adriana. Instituto Nacional de Tecnología Industrial (INTI); ArgentinaFil: Ruiz de Arechavaleta, Mariana. Instituto Nacional de Tecnología Industrial (INTI); ArgentinaFil: Davies, Stephen. National Measurement Institute (NMIA); AustraliaFil: Wang, Hongjie. National Measurement Institute (NMIA); AustraliaFil: Pires do Rego, Eliane Cristina. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Marques Rodrigues, Janaína. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: de Freitas Guimarães, Evelyn. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Barreto Sousa, Marcus Vinicius. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Monteiro, Tânia Maria. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Alves das Neves Valente, Laura. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Marques Violante, Fernando Gustavo. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Rubim, Renato. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Almeida, Ribeiro. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Baptista Quaresma, Maria Cristina. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Nogueira, Raquel. Instituto Nacional de Metrologia, Qualidade e Tecnologia (INMetro); BrasilFil: Windust, Anthony. Institute for National Measurement Standards. National Research Council Canada (NRC-INMS); CanadáFil: Dai, Xinhua. National Institute of Metrology (NIM); ChinaFil: Li, Xiaomin. National Institute of Metrology (NIM); ChinaFil: Zhang, Wei. National Institute of Metrology (NIM); ChinaFil: Li, Ming. National Institute of Metrology (NIM); ChinaFil: Shao, Mingwu. National Institute of Metrology (NIM); ChinaFil: Wei, Chao. National Institute of Metrology (NIM); ChinaFil: Wong, Siu-kay. Government Laboratory of Hong Kong SAR (GLHK); ChinaFil: Cabillic, Julie. Laboratoire National de Métrologie et d’Essais (LNE); FranciaFil: Gantois, Fanny. Laboratoire National de Métrologie et d’Essais (LNE); FranciaFil: Philipp, Rosemarie. Bundesanstalt für Materialforschung (BAM); AlemaniaFil: Pfeifer, Dietmar. Bundesanstalt für Materialforschung (BAM); AlemaniaFil: Hein, Sebastian. Bundesanstalt für Materialforschung (BAM); AlemaniaFil: Klyk-Seitz, Urszula-Anna. Bundesanstalt für Materialforschung (BAM); AlemaniaFil: Ishikawa, Keiichiro. National Metrology Institute of Japan (NMIJ); JapónFil: Castro, Esther. Centro Nacional de Metrología (CENAM); MéxicoFil: Gonzalez, Norma. Centro Nacional de Metrología (CENAM); MéxicoFil: Krylov, Anatoly. D. I. Mendeleev Institute for Metrology (VNIIM); RusiaFil: Lin, Teo Tang. Health Sciences Authority (HSA); SingapurFil: Kooi, Lee Tong. Health Sciences Authority (HSA); SingapurFil: Fernandes-Whaley, M. National Metrology Institute of South Africa (NMISA); SudáfricaFil: Prévoo, D. National Metrology Institute of South Africa (NMISA); SudáfricaFil: Archer, M. National Metrology Institute of South Africa (NMISA); SudáfricaFil: Visser, R. National Metrology Institute of South Africa (NMISA); SudáfricaFil: Nlhapo, N. National Metrology Institute of South Africa (NMISA); SudáfricaFil: de Vos, B. National Metrology Institute of South Africa (NMISA); SudáfricaFil: Ahn, Seonghee. Korea Research Institute of Standards and Science (KRISS); Corea del SurFil: Pookrod, Preeyaporn. National Institute of Metrology of Thailand (NIMT); TailandiaFil: Wiangnon, Kanjana. National Institute of Metrology of Thailand (NIMT); TailandiaFil: Sudsiri, Nittaya. National Institute of Metrology of Thailand (NIMT); TailandiaFil: Muaksang, Kittiya. National Institute of Metrology of Thailand (NIMT); TailandiaFil: Cherdchu, Chainarong. National Institute of Metrology of Thailand (NIMT); TailandiaFil: Gören, Ahmet Ceyhan. National Metrology Institute (TUBITAK UME); TurquíaFil: Bilsel, Mine. National Metrology Institute (TUBITAK UME); TurquíaFil: LeGoff, Thierry. LGC Limited; Reino UnidoFil: Bearden, Dan. National Institute of Standards and Technology (NIST); Estados UnidosFil: Bedner, Mary. National Institute of Standards and Technology (NIST); Estados UnidosFil: Duewer, David. National Institute of Standards and Technology (NIST); Estados UnidosFil: Hancock, Diane. National Institute of Standards and Technology (NIST); Estados UnidosFil: Lang, Brian. National Institute of Standards and Technology (NIST); Estados UnidosFil: Lippa, Katrice. National Institute of Standards and Technology (NIST); Estados UnidosFil: Schantz, Michele. National Institute of Standards and Technology (NIST); Estados UnidosFil: Sieber, John. National Institute of Standards and Technology (NIST); Estados Unido

NIST Interlaboratory Study on Glycosylation Analysis of Monoclonal Antibodies: Comparison of Results from Diverse Analytical Methods

Glycosylation is a topic of intense current interest in the development of biopharmaceuticals because it is related to drug safety and efficacy. This work describes results of an interlaboratory study on the glycosylation of the Primary Sample (PS) of NISTmAb, a monoclonal antibody reference material. Seventy-six laboratories from industry, university, research, government, and hospital sectors in Europe, North America, Asia, and Australia submit- Avenue, Silver Spring, Maryland 20993; 22Glycoscience Research Laboratory, Genos, Borongajska cesta 83h, 10 000 Zagreb, Croatia; 23Faculty of Pharmacy and Biochemistry, University of Zagreb, A. Kovacˇ ic´ a 1, 10 000 Zagreb, Croatia; 24Department of Chemistry, Georgia State University, 100 Piedmont Avenue, Atlanta, Georgia 30303; 25glyXera GmbH, Brenneckestrasse 20 * ZENIT / 39120 Magdeburg, Germany; 26Health Products and Foods Branch, Health Canada, AL 2201E, 251 Sir Frederick Banting Driveway, Ottawa, Ontario, K1A 0K9 Canada; 27Graduate School of Advanced Sciences of Matter, Hiroshima University, 1-3-1 Kagamiyama Higashi-Hiroshima 739–8530 Japan; 28ImmunoGen, 830 Winter Street, Waltham, Massachusetts 02451; 29Department of Medical Physiology, Jagiellonian University Medical College, ul. Michalowskiego 12, 31–126 Krakow, Poland; 30Department of Pathology, Johns Hopkins University, 400 N. Broadway Street Baltimore, Maryland 21287; 31Mass Spec Core Facility, KBI Biopharma, 1101 Hamlin Road Durham, North Carolina 27704; 32Division of Mass Spectrometry, Korea Basic Science Institute, 162 YeonGuDanji-Ro, Ochang-eup, Cheongwon-gu, Cheongju Chungbuk, 363–883 Korea (South); 33Advanced Therapy Products Research Division, Korea National Institute of Food and Drug Safety, 187 Osongsaengmyeong 2-ro Osong-eup, Heungdeok-gu, Cheongju-si, Chungcheongbuk-do, 363–700, Korea (South); 34Center for Proteomics and Metabolomics, Leiden University Medical Center, P.O. Box 9600, 2300 RC Leiden, The Netherlands; 35Ludger Limited, Culham Science Centre, Abingdon, Oxfordshire, OX14 3EB, United Kingdom; 36Biomolecular Discovery and Design Research Centre and ARC Centre of Excellence for Nanoscale BioPhotonics (CNBP), Macquarie University, North Ryde, Australia; 37Proteomics, Central European Institute for Technology, Masaryk University, Kamenice 5, A26, 625 00 BRNO, Czech Republic; 38Max Planck Institute for Dynamics of Complex Technical Systems, Sandtorstrasse 1, 39106 Magdeburg, Germany; 39Department of Biomolecular Sciences, Max Planck Institute of Colloids and Interfaces, 14424 Potsdam, Germany; 40AstraZeneca, Granta Park, Cambridgeshire, CB21 6GH United Kingdom; 41Merck, 2015 Galloping Hill Rd, Kenilworth, New Jersey 07033; 42Analytical R&D, MilliporeSigma, 2909 Laclede Ave. St. Louis, Missouri 63103; 43MS Bioworks, LLC, 3950 Varsity Drive Ann Arbor, Michigan 48108; 44MSD, Molenstraat 110, 5342 CC Oss, The Netherlands; 45Exploratory Research Center on Life and Living Systems (ExCELLS), National Institutes of Natural Sciences, 5–1 Higashiyama, Myodaiji, Okazaki 444–8787 Japan; 46Graduate School of Pharmaceutical Sciences, Nagoya City University, 3–1 Tanabe-dori, Mizuhoku, Nagoya 467–8603 Japan; 47Medical & Biological Laboratories Co., Ltd, 2-22-8 Chikusa, Chikusa-ku, Nagoya 464–0858 Japan; 48National Institute for Biological Standards and Control, Blanche Lane, South Mimms, Potters Bar, Hertfordshire EN6 3QG United Kingdom; 49Division of Biological Chemistry & Biologicals, National Institute of Health Sciences, 1-18-1 Kamiyoga, Setagaya-ku, Tokyo 158–8501 Japan; 50New England Biolabs, Inc., 240 County Road, Ipswich, Massachusetts 01938; 51New York University, 100 Washington Square East New York City, New York 10003; 52Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Roosevelt Drive, Oxford, OX3 7FZ, United Kingdom; 53GlycoScience Group, The National Institute for Bioprocessing Research and Training, Fosters Avenue, Mount Merrion, Blackrock, Co. Dublin, Ireland; 54Department of Chemistry, North Carolina State University, 2620 Yarborough Drive Raleigh, North Carolina 27695; 55Pantheon, 201 College Road East Princeton, New Jersey 08540; 56Pfizer Inc., 1 Burtt Road Andover, Massachusetts 01810; 57Proteodynamics, ZI La Varenne 20–22 rue Henri et Gilberte Goudier 63200 RIOM, France; 58ProZyme, Inc., 3832 Bay Center Place Hayward, California 94545; 59Koichi Tanaka Mass Spectrometry Research Laboratory, Shimadzu Corporation, 1 Nishinokyo Kuwabara-cho Nakagyo-ku, Kyoto, 604 8511 Japan; 60Children’s GMP LLC, St. Jude Children’s Research Hospital, 262 Danny Thomas Place Memphis, Tennessee 38105; 61Sumitomo Bakelite Co., Ltd., 1–5 Muromati 1-Chome, Nishiku, Kobe, 651–2241 Japan; 62Synthon Biopharmaceuticals, Microweg 22 P.O. Box 7071, 6503 GN Nijmegen, The Netherlands; 63Takeda Pharmaceuticals International Co., 40 Landsdowne Street Cambridge, Massachusetts 02139; 64Department of Chemistry and Biochemistry, Texas Tech University, 2500 Broadway, Lubbock, Texas 79409; 65Thermo Fisher Scientific, 1214 Oakmead Parkway Sunnyvale, California 94085; 66United States Pharmacopeia India Pvt. Ltd. IKP Knowledge Park, Genome Valley, Shamirpet, Turkapally Village, Medchal District, Hyderabad 500 101 Telangana, India; 67Alberta Glycomics Centre, University of Alberta, Edmonton, Alberta T6G 2G2 Canada; 68Department of Chemistry, University of Alberta, Edmonton, Alberta T6G 2G2 Canada; 69Department of Chemistry, University of California, One Shields Ave, Davis, California 95616; 70Horva´ th Csaba Memorial Laboratory for Bioseparation Sciences, Research Center for Molecular Medicine, Doctoral School of Molecular Medicine, Faculty of Medicine, University of Debrecen, Debrecen, Egyetem ter 1, Hungary; 71Translational Glycomics Research Group, Research Institute of Biomolecular and Chemical Engineering, University of Pannonia, Veszprem, Egyetem ut 10, Hungary; 72Delaware Biotechnology Institute, University of Delaware, 15 Innovation Way Newark, Delaware 19711; 73Proteomics Core Facility, University of Gothenburg, Medicinaregatan 1G SE 41390 Gothenburg, Sweden; 74Department of Medical Biochemistry and Cell Biology, University of Gothenburg, Institute of Biomedicine, Sahlgrenska Academy, Medicinaregatan 9A, Box 440, 405 30, Gothenburg, Sweden; 75Department of Clinical Chemistry and Transfusion Medicine, Sahlgrenska Academy at the University of Gothenburg, Bruna Straket 16, 41345 Gothenburg, Sweden; 76Department of Chemistry, University of Hamburg, Martin Luther King Pl. 6 20146 Hamburg, Germany; 77Department of Chemistry, University of Manitoba, 144 Dysart Road, Winnipeg, Manitoba, Canada R3T 2N2; 78Laboratory of Mass Spectrometry of Interactions and Systems, University of Strasbourg, UMR Unistra-CNRS 7140, France; 79Natural and Medical Sciences Institute, University of Tu¨ bingen, Markwiesenstrae 55, 72770 Reutlingen, Germany; 80Bijvoet Center for Biomolecular Research and Utrecht Institute for Pharmaceutical Sciences, Utrecht University, Padualaan 8, 3584 CH Utrecht, The Netherlands; 81Division of Bioanalytical Chemistry, Amsterdam Institute for Molecules, Medicines and Systems, Vrije Universiteit Amsterdam, de Boelelaan 1085, 1081 HV Amsterdam, The Netherlands; 82Department of Chemistry, Waters Corporation, 34 Maple Street Milford, Massachusetts 01757; 83Zoetis, 333 Portage St. Kalamazoo, Michigan 49007 Author’s Choice—Final version open access under the terms of the Creative Commons CC-BY license. Received July 24, 2019, and in revised form, August 26, 2019 Published, MCP Papers in Press, October 7, 2019, DOI 10.1074/mcp.RA119.001677 ER: NISTmAb Glycosylation Interlaboratory Study 12 Molecular & Cellular Proteomics 19.1 Downloaded from https://www.mcponline.org by guest on January 20, 2020 ted a total of 103 reports on glycan distributions. The principal objective of this study was to report and compare results for the full range of analytical methods presently used in the glycosylation analysis of mAbs. Therefore, participation was unrestricted, with laboratories choosing their own measurement techniques. Protein glycosylation was determined in various ways, including at the level of intact mAb, protein fragments, glycopeptides, or released glycans, using a wide variety of methods for derivatization, separation, identification, and quantification. Consequently, the diversity of results was enormous, with the number of glycan compositions identified by each laboratory ranging from 4 to 48. In total, one hundred sixteen glycan compositions were reported, of which 57 compositions could be assigned consensus abundance values. These consensus medians provide communityderived values for NISTmAb PS. Agreement with the consensus medians did not depend on the specific method or laboratory type. The study provides a view of the current state-of-the-art for biologic glycosylation measurement and suggests a clear need for harmonization of glycosylation analysis methods. Molecular & Cellular Proteomics 19: 11–30, 2020. DOI: 10.1074/mcp.RA119.001677.L