U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Search Publications by: Johanna Camara (Fed)

Search Title, Abstract, Conference, Citation, Keyword or Author
Displaying 1 - 25 of 42

Recommendations for setting a criterion and assessing commutability of sample materials used in external quality assessment/proficiency testing schemes

November 2, 2023
Author(s)
Sverre Sandberg, Pernille Fauskanger, Jesper Johansen, Thomas Keller, Jeffrey Budd, Neil Greenberg, robert rej, MAURO PANTEGHINI, VINCENT DELATOUR, Ferruccio Ceriotti, Liesbet Deprez, Johanna Camara, Finlay MacKenzie, Alicia Lyle, Eline van der Hagen, Chris Burns, W. Greg Miller
It is important for external quality assessment materials (EQAMs) to be commutable with clinical samples; i.e., they should behave like clinical samples when measured using end-user clinical laboratory in vitro diagnostic medical devices (IVD-MDs). Using

Recommendations for Setting a Criterion for Assessing Commutability of Secondary Calibrator Certified Reference Materials

August 11, 2023
Author(s)
W. Greg Miller, Thomas Keller, Jeffrey Budd, Jesper Johansen, Mauro Panteghini, Neil Greenberg, Vincent Delatour, Ferruccio Ceriotti, Robert Rej, Johanna Camara, Liesbet Deprez, Finlay MacKenzie, Alicia Lyle, Eline van der Hagen, Chris Burns, Pernille Fauskanger, Sverre Sandberg
A secondary higher-order calibrator is required to be commutable with clinical samples to be suitable for use in the calibration hierarchy of an end-user clinical laboratory in vitro diagnostic medical device (IVD-MD). Commutability is a property of a

Determination of 24,25-dihydroxyvitamin D3 in Vitamin D External Quality Assessment Scheme samples using a reference measurement procedure

May 9, 2023
Author(s)
Stephen Wise, Grace Hahm, Carolyn Burdette, Susan Tai, Johanna Camara, Adam Kuszak, Emma Williams
Ninety archived human serum samples from the Vitamin D External Quality Assessment Scheme (DEQAS) were analyzed using a reference measurement procedure (RMP) based on isotope dilution liquid chromatography - tandem mass spectrometry (ID LC-MS/MS) for the

Development of an Improved Standard Reference Material for Folate Vitamers in Human Serum

December 12, 2022
Author(s)
Johanna Camara, Jeanita Pritchett, Yasmine Daniels, Mary Bedner, Michael Nelson, Mark Lowenthal, Zia Fazili, Christine Pfeiffer, Karen W. Phinney, Katherine E. Sharpless, Lane C. Sander, Katrice Lippa, James H. Yen, Adam Kuszak, Stephen Wise
The US National Institute of Standards and Technology (NIST) developed a Standard Reference Material® (SRM®) 3949 Folate Vitamers in Frozen Human Serum to replace SRM 1955 Homocysteine and Folate in Human Serum. The presence of increased endogenous levels

Assessment of Serum Total 25-Hydroxyvitamin D Assays for Vitamin D External Quality Assessment Scheme (DEQAS) Materials Distributed at Ambient and Frozen Conditions

November 9, 2021
Author(s)
Johanna Camara, Christopher T. Sempos, Emma L. Williams, Graham D. Carter, Julia C. Jones, Carolyn Burdette, Grace Hahm, Federica Nalin, David L. Duewer, Adam J. Kuszak, J. M. Betz, Andrew Hoofnagle, Pierre Lukas, E. Cavalier, Ramon Durazo-Arvizu, P. M. Crump, Christian Popp, Christian Beckert, Glen Van Slooten, Patrick Gradon, Joelle Morgand, Sarah Paul, Bruno Emanuelli, Angelo Maggio, Fiona Ivison, Ralf Fischer, Jody M. van den Ouweland, Chung S. Ho, Emmett W. Law, Jean-Nicolas Simard, Renaud Gonthier, Brett Holmquist, Manisha S. Patwardhan, Marcelo C. Batista, Heather Pham, Sarah Meadows, Eugene Jansen, Dilshad A. Khan, Kimberly Robyak, Mark Kilbane, Neil Parker, Vincent Chen, Robert Fitzgerald, Sohail Mushtaq, Michael W. Clarke, Norma Breen, Christine Simpson, Stephen A. Wise
The Vitamin D External Quality Assessment Scheme (DEQAS) distributes human serum samples four times per year to over 1000 participants worldwide for the determination of total serum 25-hydroxyvitamin D [25(OH)D)]. These samples are stored at −40 °C prior

Optimizing Available Tools for Obtaining Result Standardization: A Joint Committee on Traceability in Laboratory Medicine (JCTLM) Project

October 12, 2021
Author(s)
Mauro Panteghini, Federica Braga, Johanna Camara, Vincent Delatour, Katleen Van Uytfanghe, Hubert Vesper, Tianjiao Zhang
BACKGROUND: The JCTLM created a Task Force on Reference Measurement System Implementation (TFRMSI) to provide guidance on metrological traceability implementation for the in vitro diagnostics (IVD) community. CONTENT: TF-RMSI investigated the reference

Metrological Tools for the Reference Materials and Reference Instruments of the NIST Material Measurement Laboratory

September 16, 2021
Author(s)
Carlos R. Beauchamp, Johanna Camara, Jennifer Carney, Steven J. Choquette, Kenneth D. Cole, Paul C. DeRose, David L. Duewer, Michael Epstein, Margaret Kline, Katrice Lippa, Enrico Lucon, John L. Molloy, Michael Nelson, Karen W. Phinney, Maria Polakoski, Antonio Possolo, Lane C. Sander, John E. Schiel, Katherine E. Sharpless, Michael R. Winchester, Donald Windover
The National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards, was established by the U.S. Congress in 1901 and charged with establishing a measurement foundation to facilitate U.S. and international commerce. NIST

Certification of Standard Reference Materials(R) 2969 and 2970: Vitamin D Metabolites in Frozen Human Serum (Total 25-Hydroxyvitamin D Low Level) and (25-Hydroxyvitamin D2 High Level)

September 2, 2021
Author(s)
Grace Hahm, Michael Nelson, Johanna Camara, Blaza Toman
Standard Reference Materials (SRMs) 2969 and 2970 are intended for 1) use in validating methods for determining concentrations of 25-hydroxyvitamin D2 (25(OH)D2) and 25-hydroxyvitamin D3 (25(OH)D3) in human serum and plasma and 2) value assigning in house

Interlaboratory Comparison of 25-Hydroxyvitamin D Assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 2 Immunoassays - Impact of 25 Hydroxyvitamin D2 and 24R,25-Dihydroxyvitamin D3 on Assay Performance

August 27, 2021
Author(s)
Stephen Wise, Johanna Camara, Carolyn Burdette, Grace Hahm, Federica Nalin, Adam Kuszak, Joyce Merkel, Ramon Durazo-Arvizu, Emma Williams, Christian Popp, Christian Beckert, Jan Schultess, Glen Van Slooten, Carole Tourneur, Camille Pease, Kavi Kaul, Alfredo Villarreal, Marcelo Batista, Heather Pham, Alex Bennett, Eugene Jansen, Dilshad Khan, Mark Kilbane, Patrick Twomey, James Freeman, Neil Parker, Sohail Mushtaq, Christine Simpson, Pierre Lukas, Etienne Cavalier, Christopher Sempos
An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of immunoassays (Part 2) for the determination of serum total 25 hydroxyvitamin D [25(OH)D]. A set of 50 single-donor samples was

Interlaboratory Comparison of 25-Hydroxyvitamin D Assays: Vitamin D Standardization Program (VDSP) Intercomparison Study 2 - Part 1 Liquid Chromatography - Tandem Mass Spectrometry (LC-MS/MS) Assays - Impact of 3-epi-25-Hydroxyvitamin D3

August 27, 2021
Author(s)
Stephen Wise, Johanna Camara, Carolyn Burdette, Grace Hahm, Federica Nalin, Adam Kuszak, Joyce Merkel, Ramon Durazo-Arvizu, Emma Walker, Andrew Hoofnagle, Fiona Ivison, Ralf Fischer, Jody van den Ouweland, Chung Ho, Emmet Law, Jean-Nicolas Simard, Renaud Gonthier, Brett Holmquist, Sarah Meadows, Lorna Cox, Kimberly Robyak, Michael Creer, Robert Fitzgerald, Michael Clarke, Norma Breen, Pierre Lukas, Etienne Cavalier, Christopher Sempos
An interlaboratory comparison study was conducted by the Vitamin D Standardization Program (VDSP) to assess the performance of liquid chromatography – tandem mass spectrometry (LC-MS/MS) assays used for the determination of serum total 25-hydroxyvitamin D

Assessment of Serum Total 25 Hydroxyvitamin D Assay Commutability of Standard Reference Materials and College of American Pathologists Accuracy Based Vitamin D (ABVD) Scheme and Vitamin D External Quality Assessment Scheme (DEQAS) Materials: Vitamin D Sta

July 1, 2021
Author(s)
Johanna Camara, Stephen A. Wise, Andrew Hoofnagle, Emma L. Williams, Graham D. Carter, Julia C. Jones, Carolyn Burdette, Grace Hahm, Federica Nalin, Adam J. Kuszak, Joyce M. Merkel, Ramon Durazo-Arvizu, Pierre Lukas, E. Cavalier, Christian Popp, Christian Beckert, Jan Schultess, Glen Van Slooten, Carole Tourneur, Camille Pease, Ravi Kaul, Alfredo Villarreal, Fiona Ivison, Ralf Fischer, Jody M. van den Ouweland, Chung S. Ho, Emmett W. Law, Jean-Nicolas Simard, Renaud Gonthier, Brett Holmquist, Marcelo C. Batista, Heather Pham, Alex Bennett, Sarah Meadows, Lorna Cox, Eugene Jansen, Dilshad A. Khan, Kimberly Robyak, Michael H. Creer, Mark Kilbane, Patrick J. Twomey, James Freeman, Neil Parker, Jinyun Yuan, Robert Fitzgerald, Sohail Mushtaq, Michael W. Clarke, Norma Breen, Christine Simpson, Christopher T. Sempos
An interlaboratory study was conducted through the Vitamin D Standardization Program (VDSP) to assess commutability of Standard Reference Materials® (SRMs) and proficiency testing/external quality assessment (PT/EQA) samples for determination of serum

Vitamin D Standardization Program (VDSP) intralaboratory study for the assessment of 25-hydroxyvitamin D assay variability and bias

May 17, 2021
Author(s)
Johanna Camara, Stephen Wise, Christopher T. Sempos, Pierre Lukas, Caroline LeGoff, Stephanie Peeters, Carolyn Burdette, Federica Nalin, Grace Hahm, Ramon Durazo-Arvizu, Adam J. Kuszak, Joyce M. Merkel, E. Cavalier
An intralaborabory comparison study to assess the performance of assays for the determination of serum total 25-hydroxyvitamin D [25(OH)D] was conducted in 2017 as part of the Vitamin D Standardization Program (VDSP). The intralaboratory study consisted of

Metrological Tools for the Reference Materials and Reference Instruments of the NIST Material Measurement Laboratory

July 15, 2020
Author(s)
Carlos R. Beauchamp, Johanna Camara, Jennifer Carney, Steven J. Choquette, Kenneth D. Cole, Paul C. DeRose, David L. Duewer, Michael Epstein, Margaret C. Kline, Katrice Lippa, Enrico Lucon, Karen W. Phinney, Maria Polakoski, Antonio Possolo, Katherine E. Sharpless, John R. Sieber, Blaza Toman, Michael R. Winchester, Donald Windover
The National Institute of Standards and Technology (NIST), formerly the National Bureau of Standards, was established by the U.S. Congress in 1901 and charged with establishing a measurement foundation to facilitate U.S. and international commerce. NIST

IFCC working group recommendations for correction of bias caused by non-commutability of a certified reference material used in the calibration hierarchy of an end-user measurement procedure

June 1, 2020
Author(s)
Johanna Camara, W. Greg Miller, Jeffrey R. Budd, Neil Greenberg, Weykamp Cas, Harald Althaus, Heinz Schimmel, Mauro Panteghini, Vincent Delatour, Ferruccio Ceriotti, Thomas Keller, Douglas Hawkins, Robert Rej, Finlay MacKenzie, Elina van der Hagen, Hubert W. Vesper
Establishing metrological traceability to a matrix-based certified reference material (CRM) that has been validated to be commutable among a group of measurement procedures (MPs) is central to producing equivalent results for a measurand in clinical

An updated protocol based on CLSI document C37 for preparation of off-the-clot serum from individual units for use alone or to prepare commutable pooled serum reference materials

October 30, 2019
Author(s)
Johanna Camara, Uliana Danilenko, Hubert W. Vesper, Gary L. Myers, Patric A. Clapshaw, W. Greg Miller
Manufacturers of in-vitro diagnostic medical devices, clinical laboratories, research laboratories and calibration laboratories require commutable reference materials that can be used in the calibration hierarchies of medical laboratory measurement

Enhancing the Accuracy of Measurement of Small Molecule Organic Biomarkers

October 30, 2019
Author(s)
Tang Lin Teo, Katrice Lippa, Lindsey Mackay, Sharon Yong, Qinde Liu, Johanna Camara, Vincent Delatour, Tong Kooi Lee, Beatrice Lalere, Gavin O'Connor, Andr? Henrion, Megumi Kato, Jane L. Fernandes, Masahiko Numata, Ha-Jeong Kwon, Ji-Seon Jeong, Bei Xu, Jintana Nammoommoy, Dewei Song, Wagner Wollinger
Over two decades, the Organic Analysis Working Group (OAWG) of the Consultative Committee for Amount of Substance (CCQM) has organised a number of comparisons for clinically relevant small molecule organic biomarkers. These comparisons are hinged upon the

Health Assessment Measurements Quality Assurance Program: Exercise 2 Final Report

May 21, 2019
Author(s)
Charles A. Barber, Jeanice M. Brown Thomas, Carolyn Q. Burdette, Johanna Camara, Stephen E. Long, Melissa M. Phillips, Benjamin J. Place, Catherine A. Rimmer, Laura J. Wood, Lee L. Yu
The NIST Health Assessment Measurements Quality Assurance Program (HAMQAP) was launched in collaboration with the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) in 2017. HAMQAP was established to enable laboratories to improve the

Health Assessment Measurements Quality Assurance Program: Exercise 1 Final Report

November 19, 2018
Author(s)
Chuck Barber, Bruce A. Benner Jr., Jeanice M. Brown Thomas, Carolyn Burdette, Johanna Camara, Stephen E. Long, Jacolin Murray, Melissa M. Phillips, Benjamin Place, Kate Rimmer, Laura J. Wood, Susan Tai, Siva K. Chinthalapati, Lee L. Yu
The NIST Health Assessment Measurements Quality Assurance Program (HAMQAP) was launched in collaboration with the National Institutes of Health (NIH) Office of Dietary Supplements (ODS) in 2017. HAMQAP was established to enable laboratories to improve the

Standard Reference Material 2378 Fatty Acids in Frozen Human Serum. A Clinical SRM based on Endogenous Supplementation of Polyunsaturated Fatty Acids

February 13, 2018
Author(s)
Bruce A. Benner Jr., Michele M. Schantz, Johanna Camara, Katherine E. Sharpless, James H. Yen, Lorna T. Sniegoski, Carissa D. Powers, Rosemary L. Schleicher
Dietary fatty acids can be both beneficial and detrimental to human health depending on the degree and type of saturation. Healthcare providers and research scientists monitor the fatty acid content of human plasma and serum as an indicator of health

Recommendations for assessing commutability part 1: general experimental design

January 18, 2018
Author(s)
Johanna Camara, W. Greg Miller, Schimmel Heinz, Neil Greenberg, Chris Burns, Vincent Delatour, Mauro Panteghini, Hubert W. Vesper, Robert Rej, Ferruccio Ceriotti, Gerhard Schumann, Jeffrey R. Budd, Weykamp Cas, Goran Nilsson, Finlay MacKenzie, Thomas Keller
Commutability is a property of a reference material that relates to the closeness of agreement between results for a reference material and results for clinical samples when measured by two or more measurement procedures. Commutability of reference

Recommendations for assessing commutability part 2: based on the difference in bias between a reference material and clinical samples

January 18, 2018
Author(s)
Johanna Camara, Goran Nilsson, Jeffrey R. Budd, Neil Greenberg, Vincent Delatour, Gerhard Schumann, Robert Rej, Mauro Panteghini, Ferruccio Ceriotti, Schimmel Heinz, Weykamp Cas, Thomas Keller, Chris Burns, Finlay MacKenzie, W. Greg Miller
A process is described to assess the commutability of a reference material intended for use as a calibrator, trueness control or external quality assessment sample based on the difference in bias between a reference material and clinical samples measured