Multilaboratory Testing Research Articles

Analysis of Bovine Lactoferrin in Infant Formula and Adult Nutritional Products by Optical Biosensor Immunoassay: Collaborative Study, Final Action 2021.07.

Bovine lactoferrin is increasingly being used as an ingredient in infant formula manufacture to enhance nutritional efficacy through the provision of growth, immunoprotective, and antimicrobial factors to the neonate. To evaluate method reproducibility of AOAC First Action Official Method 2021.07 for compliance with the performance requirements described in Standard Method Performance Requirement (SMPR®) 2020.005. Eight laboratories participated in the analysis of blind-duplicate samples of seven nutritional products. Samples were diluted in buffer, and an optical biosensor immunoassay was used in a direct-assay format to quantitate bovine lactoferrin by its interaction with an immobilized anti-lactoferrin antibody. Quantitation was accomplished by the external standard technique with interpolation from a four-parameter calibration regression. After outliers were removed, precision as reproducibility was found to be within limits set in SMPR 2020.005 (≤ 9%) for six out of seven samples and all had acceptable Horwitz Ratio (HorRatR) values ranging from 1.0 to 2.1. Additionally, comparison with an alternative independent Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) First Action method (heparin cleanup LC-UV), showed negligible difference between results. The method described is suitable for the quantification of intact, undenatured bovine lactoferrin in powdered infant formulas. The SPIFAN Expert Review Panel evaluated the method and accompanying validation data from this multi-laboratory testing (MLT) study in July 2023 and recommended Official Method 2021.07 for adoption as a Final Action Official MethodSM. A multi-laboratory validation study of an automated optical biosensor immunoassay for the determination of intact, undenatured bovine lactoferrin is described.

Simultaneous Determination of Total Vitamins B1, B2, B3, and B6 in Infant Formula and Related Nutritionals by Enzymatic Digestion and LC-MS/MS-A Multi-Laboratory Testing Study Final Action: AOAC Method 2015.14.

A multi-laboratory study was completed for AOAC First Action Method 2015.14. Ten laboratories from eight countries participated. Each laboratory analyzed (in duplicate) a placebo and 14 fortified nutritionals. Product matrices analyzed included milk, soy, partially hydrolyzed milk, partially hydrolyzed soy, and elemental-based infant formula powders, milk based infant formula ready-to-feed liquids, adult low-fat powders, and adult high fat and high protein ready-to-drink nutritionals. Data was then compared to standard method performance requirements (SMPR). Samples were prepared by enzymatic digestion with papain, α-amylase, and phosphatase to hydrolyze protein and complex carbohydrate and to free phosphorylated vitamin forms respectively. Stable-isotope labeled internal standards were incorporated into the sample preparation to correct for variability in both the sample preparation and instrument response. Prepared samples and working standard solutions were injected onto an ultra-high-pressure liquid chromatograph, interfaced to a triple-quadrupole mass spectrometer (MS/MS). Reverse phase gradient chromatography, using mobile phases of methanol and 20 mM ammonium formate in water on a C-18 column, were used for the analysis. The MS/MS was configured to monitor precursor-fragment ion pairs for each analyte and internal standard. Vitamins B1 (thiamine), B2 (riboflavin), B3 (niacin), and B6 (pyridoxine) were quantified by least squares regression using the response ratio of the analyte to its internal standard. Total vitamins B1, B2, B3, and B6 had average repeatability of 2.3%, 3.9%, 2.7%, and 2.2% RSD, and reproducibility of 8.2%, 6.9%, 6.7%, and 5.8% RSD, respectively. Repeatability and reproducibility SMPR were met for 53/56 and 50/56 fortified-product/analyte pairs analyzed, respectively.

Determination of Free and Total Choline and Free and Total Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (HPLC-MS/MS): A Multi-laboratory Testing Study, Final Action 2015.10.

A multi-laboratory study was conducted on AOAC First Action Method 2015.10 "Determination of Free and Total Choline and Free and Total Carnitine in Infant Formula and Adult/Pediatric Nutritional Formula by Liquid Chromatography/Tandem Mass Spectrometry (HPLC-MS/MS)." In this study, nine laboratories participated in the performance testing of the method using ten nutritional products tested as blind duplicates. Both free and total carnitine and free and total choline content of the samples were determined using separate extractions for the free and total results. For free choline and carnitine analysis, samples are diluted in water. For total choline and carnitine analysis, samples are extracted using acid-assisted microwave hydrolysis with nitric acid. For both the free and total methods, samples are then diluted with acetonitrile and analyzed using strong cation exchange (SCX) liquid chromatography coupled to a triple quadrupole tandem mass spectrometer (LCMS). Stable isotope labeled internal standards were utilized in all analyses to compensate for extraction inefficiencies and ionization suppression.

HPLC Determination of Total Tryptophan in Infant Formula and Adult/Pediatric Nutritional Formula Following Enzymatic Hydrolysis, Multilaboratory Testing Study: Final Action 2017.03

Abstract Background: A multi-laboratory study was completed with AOAC First Action Method 2017.03, HPLC Determination of Total Tryptophan in Infant Formula and Adult/Pediatric Nutritional Formula Following Enzymatic Hydrolysis. Objective: Ten laboratories from seven countries participated in the multi-laboratory study. Each laboratory analyzed 14 infant, pediatric, and adult nutritionals in duplicate. Product matrices analyzed included milk, soy, partially hydrolyzed milk, partially hydrolyzed soy, and elemental-based infant formula powders, milk-based infant formula ready-to-feed (RTF) liquids, adult low-fat powders, and adult high-fat and high-protein ready-to-drink nutritionals. Methods: Tryptophan was released from the intact protein in product matrices with a combination of proteolytic enzymes found in pronase. Following proteolysis, tryptophan was quantitated by reverse-phase isocratic HPLC and fluorescence detection. Prepared samples were injected onto a C8 HPLC column with a methanol/0.05 M phosphate buffer mobile phase. Results: Overall for tryptophan, repeatability averaged 2.1% relative SD (RSD) with a range of 0.9–3.6% RSD, and reproducibility averaged 4.2% RSD with a range of 3.0–9.9% RSD. Conclusions: Repeatability Standard Method Performance Requirements (SMPRs®) were met for 13 of the 14 matrices and reproducibility SMPRs were met for 11 of the 14 product matrices analyzed.

HPLC Determination of Total Tryptophan in Infant Formula and Adult/Pediatric Nutritional Formula Following Enzymatic Hydrolysis, Multilaboratory Testing Study: Final Action 2017.03.

Background: A multi-laboratory study was completed with AOAC First Action Method 2017.03, HPLC Determination of Total Tryptophan in Infant Formula and Adult/Pediatric Nutritional Formula Following Enzymatic Hydrolysis. Objective: Ten laboratories from seven countries participated in the multi-laboratory study. Each laboratory analyzed 14 infant, pediatric, and adult nutritionals in duplicate. Product matrices analyzed included milk, soy, partially hydrolyzed milk, partially hydrolyzed soy, and elemental-based infant formula powders, milk-based infant formula ready-to-feed (RTF) liquids, adult low-fat powders, and adult high-fat and high-protein ready-to-drink nutritionals. Methods: Tryptophan was released from the intact protein in product matrices with a combination of proteolytic enzymes found in pronase. Following proteolysis, tryptophan was quantitated by reverse-phase isocratic HPLC and fluorescence detection. Prepared samples were injected onto a C8 HPLC column with a methanol/0.05 M phosphate buffer mobile phase. Results: Overall for tryptophan, repeatability averaged 2.1% relative SD (RSD) with a range of 0.9-3.6% RSD, and reproducibility averaged 4.2% RSD with a range of 3.0-9.9% RSD. Conclusions: Repeatability Standard Method Performance Requirements (SMPRs®) were met for 13 of the 14 matrices and reproducibility SMPRs were met for 11 of the 14 product matrices analyzed.

Determination of trans and Total Vitamin K1 in Infant, Pediatric, and Adult Nutritionals by HPLC with Post Column Reduction and Fluorescence Detection: Multilaboratory Testing Study, AOAC Final Action 2015.09.

A multilaboratory study was completed with AOAC INTERNATIONAL First Action Official MethodSM 2015.09, "Determination of trans and Total (cis+trans) Vitamin K1 in Infant, Pediatric, and Adult Nutritionals by HPLC with Post Column Reduction and Fluorescence Detection." Eight laboratories from six countries participated in the multilaboratory study. Each laboratory analyzed 19 infant, pediatric, and adult nutritionals in duplicate. The product matrixes analyzed included milk, soy, partially hydrolyzed milk, partially hydrolyzed soy, and elemental-based infant formula powders; milk-based infant formula ready-to-feed liquids; pediatric powders; adult low- and high-fat powders; and high-protein ready-to-drink nutritionals. Vitamin K1 was extracted from product matrixes with isooctane after precipitation of proteins and the release of lipids with methanol. Prepared samples were injected onto a silica HPLC column in which cis and trans vitamin K1 were separated with an isooctane-isopropanol mobile phase. The column eluent was mixed with a dilute ethanolic solution of zinc chloride, sodium acetate, and acetic acid, and cis and trans vitamin K1 were reduced to fluorescent derivatives in a zinc reactor column. Overall, trans vitamin K1 repeatability averaged 3.06% relative standard deviation (RSD) with a range of 0.99-7.16% RSD and reproducibility averaged 6.36% RSD with a range of 3.15-16.1% RSD. Repeatability Standard Method Performance Requirements (SMPR®) were met for all 19 matrixes, and reproducibility SMPRs were met for 18 of the 19 product matrixes analyzed. Repeatability and reproducibility for total (cis + trans) vitamin K1 averaged 3.15% RSD with a range of 1.06-6.87% RSD and 6.11% RSD with a range of 2.94-16.7% RSD, respectively.

Total Folate in Infant Formula and Adult Nutritionals by Trienzyme Extraction and LC-MS/MS Quantitation: A Multilaboratory Testing Study, Final Action 2011.06

Background: The need for an updated reference method for folate was identified as a priority by the AOAC's Stakeholder Panel on Infant Formula and Adult Nutritionals (SPIFAN) in 2011. An Expert Review Panel (ERP) found AOAC Official MethodSM 2011.06 suitable for the purpose and approved it as a First Action Official Method. Objective: To determine the repeatability and reproducibility of Method 2011.06: Total Folate in Infant Formula and Adult Nutritionals by Trienzyme Extraction and LC-MS/MS Quantitation. Methods: A multilaboratory collaborative study was conducted. Eleven laboratories located in five countries participated and completed analysis of all multilaboratory testing (MLT) samples. The study was divided into two parts. In the first part, the laboratories analyzed two practice samples (blindly coded) using the updated folate Method 2011.06. The laboratories providing results within the expected range qualified for part two, in which they analyzed 11 MLT samples in blind duplicates. Results: The results were compared with the Standard Method Performance Requirements (SMPR 2011.006) established for folate. The precision results met the requirements stated in the SMPR for all of the samples. Repeatability and reproducibility relative standard deviations ranged from 3.5 to 6.6 and from 9.0 to 15.7%, respectively. Horwitz ratio values for all of the samples were well below 2 (0.61-1.06). Conclusions: The ERP determined that the method performance met the SMPR requirements in September 2017 after reviewing the presented MLT data. Highlights: The ERP recommended the method for Final Action status.

Determination of Total Biotin by Liquid Chromatography Coupled with Immunoaffinity Column Cleanup Extraction: Multilaboratory Testing, Final Action 2016.02.

Single- and multilaboratory testing data have provided systematic scientific evidence that a simple, selective, accurate, and precise method can be used as a potential candidate reference method for dispute resolution in determining total biotin in all forms of infant, adult, and/or pediatric formula. Using LC coupled with immunoaffinity column cleanup extraction, the method fully meets the intended purpose and applicability statement in AOAC Standard Method Performance Requirement 2014.005. The method was applied to a cross-section of infant formula and adult nutritional matrixes, and acceptable precision and accuracy were established. The analytical platform is inexpensive, and the method can be used in almost any laboratory worldwide with basic facilities. The immunoaffinity column cleanup extraction is the key step to successful analysis.

Analysis of Vitamin D₂ and Vitamin D₃ in Infant and Adult Nutritional Formulas by Liquid Chromatography-Tandem Mass Spectrometry: A Multilaboratory Testing Study.

A multilaboratory testing study was conducted on AOAC First Action Method 2016.05 "Analysis of Vitamin D2 and Vitamin D3 in Fortified Milk Powders, Infant Formulas, and Adult/Pediatric Nutritional Formulas by Liquid Chromatography-Tandem Mass Spectrometry." Nine laboratories participated in the analysis of duplicate samples of 20 nutritional products. The samples were saponified at high temperature with lipid-soluble components extracted into isooctane; an aliquot was washed and vitamin D derivatized with 4-phenyl-1,2,4-triazoline-3,5-dione to form a high-molecular mass, easily ionizable adduct, extracted into acetonitrile and analyzed by reversed-phase LC-tandem MS. Stable isotope-labeled internal standards were used for quantitation to correct for losses in extraction and variation in derivatization and ionization efficiencies. Acceptable precision as RSD was demonstrated; repeatability ranged from 1.9 to 5.8% RSDr and reproducibility values ranged from 6.4 to 12.7% RSDR, with samples meeting the precision limits specified in the vitamin D Standard Method Performance Requirements and the guidelines recommended for the Horwitz ratio. Method accuracy was assessed using NIST 1849a Standard Reference Material, with a P-value of 0.32, indicating an absence of bias against the certified value. As expected, placebo samples not fortified with vitamin D returned negligible results.

Mechanical characterisation of structural laminated bamboo

Low carbon construction materials are needed to reduce carbon dioxide emissions in the built environment. Laminated bamboo is an example of such a material. However, to be used in structural applications, fundamental mechanical properties are needed to establish the design values used in architecture and engineering practice. Recent studies on laminated bamboo have focused on the use of timber standards for small clear specimens, with little work published on structural-scale testing. The work presented in this paper is the first study to utilise structural-scale test methods for timber in a multi-laboratory test programme to investigate all mechanical properties of an outdoor laminated bamboo product. The study provides a comparison of the full-scale structural performance with conventional timber and a pathway for use in engineering design and practice. The work shows that laminated bamboo is comparable to conventional timber and timber-based products in structural properties and forms a foundation for the use of laminated bamboo in design and construction.

Validation of Single and Pooled Manure Drag Swabs for the Detection of Salmonella Serovar Enteritidis in Commercial Poultry Houses.

Single swabs (cultured individually) are currently used in the Food and Drug Administration (FDA) official method for sampling the environment of commercial laying hens for the detection of Salmonella enterica ssp. serovar Enteritidis (Salmonella Enteritidis). The FDA has also granted provisional acceptance of the National Poultry Improvement Plan's (NPIP) Salmonella isolation and identification methodology for samples taken from table-egg layer flock environments. The NPIP method, as with the FDA method, requires single-swab culturing for the environmental sampling of laying houses for Salmonella Enteritidis. The FDA culture protocol requires a multistep culture enrichment broth, and it is more labor intensive than the NPIP culture protocol, which requires a single enrichment broth. The main objective of this study was to compare the FDA single-swab culturing protocol with that of the NPIP culturing protocol but using a four-swab pool scheme. Single and multi-laboratory testing of replicate manure drag swab sets (n = 525 and 672, respectively) collected from a Salmonella Enteritidis-free commercial poultry flock was performed by artificially contaminating swabs with either Salmonella Enteritidis phage type 4, 8, or 13a at one of two inoculation levels: low, x¯ = 2.5 CFU (range 2.5-2.7), or medium, x¯ = 10.0 CFU (range 7.5-12). For each replicate, a single swab (inoculated), sets of two swabs (one inoculated and one uninoculated), and sets of four swabs (one inoculated and three uninoculated), testing was conducted using the FDA or NPIP culture method. For swabs inoculated with phage type 8, the NPIP method was more efficient (P < 0.05) for all swab sets at both inoculation levels than the reference method. The single swabs in the NPIP method were significantly (P < 0.05) better than four-pool swabs in detecting Salmonella Enteritidis at the lower inoculation level. In the collaborative study (n = 13 labs) using Salmonella Enteritidis phage type 13a inoculated swabs, there was no significant difference (P > 0.05) between the FDA method (single swabs) and the pooled NPIP method (four-pool swabs). The study concludes that the pooled NPIP method is not significantly different from the FDA method for the detection of Salmonella Enteritidis in drag swabs in commercial poultry laying houses. Consequently based on the FDA's Salmonella Enteritidis rule for equivalency of different methods, the pooled NPIP method should be considered equivalent. Furthermore, the pooled NPIP method was more efficient and cost effective.

Multilaboratory testing of antifungal drug combinations against Candida species and Aspergillus fumigatus: utility of 100 percent inhibition as the endpoint.

Four laboratories tested three isolates of Candida species and two isolates of Aspergillus fumigatus using 96-well plates containing combinations of amphotericin B, anidulafungin, caspofungin, micafungin, fluconazole, itraconazole, posaconazole, and voriconazole. The majority of summation fractional inhibitory concentration indices (ΣFICI) based on the Lowe additivity formula suggested indifferent drug interactions (ΣFICI > 0.5 and ≤4.0) and no instance of drug antagonism (ΣFICI > 4.0). The intra- and interlaboratory agreement rates were superior when MIC100 readings were used as endpoints (at a 99% confidence interval [CI]).

Statistical evaluation of data from multi-laboratory testing of a measurement method intended to indicate the presence of dust resulting from the collapse of the World Trade Center

In this paper we describe a statistical analysis of the inter-laboratory data summarized in Rosati et al. (2008) to assess the performance of an analytical method to detect the presence of dust from the collapse of the World Trade Center (WTC) on September 11, 2001. The focus of the inter-lab study was the measurement of the concentration of slag wool fibers in dust which was considered to be an indicator of WTC dust. Eight labs were provided with two blinded samples each of three batches of dust that varied in slag wool concentration. Analysis of the data revealed that three of labs, which did not meet measurement quality objectives set forth prior to the experimental work, were statistically distinguishable from the five labs that did meet the quality objectives. The five labs, as a group, demonstrated better measurement capability although their ability to distinguish between the batches was somewhat mixed. This work provides important insights for the planning and implementation of future studies involving examination of dust samples for physical contaminants. This work demonstrates (a) the importance of controlling the amount of dust analyzed, (b) the need to take additional replicates to improve count estimates, and (c) the need to address issues related to the execution of the analytical methodology to ensure all labs meet the measurement quality objectives.

Von Willebrand disease and other bleeding disorders in women: consensus on diagnosis and management from an international expert panel

Reproductive tract bleeding in women is a naturally occurring event during menstruation and childbirth. In women with menorrhagia, however, congenital bleeding disorders historically have been underdiagnosed. This consensus is intended to allow physicians to better recognize bleeding disorders as a cause of menorrhagia and consequently offer effective disease-specific therapies.

Furnace Testing of Full-Scale Gypsum Steel Stud Non-Load Bearing Wall Assemblies: Results of Multi-Laboratory Testing in Canada, Japan, and USA

The present paper discusses the results of a multiple laboratory test program aimed at determining the consistency of large scale furnace testing. The North American Fire Testing Laboratories (NAFTL) consortium organized a multiple laboratory test program for ASTM E119-00 using a common structural element: a 1-h rated gypsum/steel-stud non-load bearing wall assembly. Walls were tested by six different organizations employing 10 different furnace facilities following the guidance provided in ASTM E119-00. In addition to NAFTL members conducting the tests, the program was expanded to include four testing laboratories in Japan; the Center for Better Living served as the organizer for the Japanese testing. Results obtained from these experiments are discussed.

Proficiency Test for Chemical Laboratories for the Analysis of a Pesticide in a Formulated Product: Interlaboratory Study

A multilaboratory proficiency testing program was conducted by the National Accreditation Board for Testing and Calibration Laboratories (India) and coordinated by the Institute of Pesticide Formulation Technology. This program was conducted to compare the performance of individual laboratories in the area of pesticide formulation (Chlorpyrifos 20 EC) analysis. A total of 24 laboratories in India participated. Analysis of 2 parameters (i.e., estimation of the active ingredient and the acidity) of 2 samples of Chlorpyrifos 20 EC was the objective of this program. Homogeneity tests were performed before sample distribution. Performance of the participating laboratories was evaluated by using new robust statistics given in the guidelines of the National Association of Testing Authorities, Australia. Results were collated and statistically computed to calculate the value of 2 types of Z-scores (Zwi and Zbi). In addition to the statistical analysis, a graphical representation such as the Youden plot was also generated to evaluate the performance of participating laboratories.

Multilaboratory Testing of Antifungal Combinations against a Quality Control Isolate of Candida krusei

Candida krusei ATCC 6258 was tested by eight laboratories using 96-well plates containing checkerboard pairwise combinations of amphotericin B (AMB), posaconazole (PSC), caspofungin (CSP), and voriconazole (VRC). The methodology led to reproducible results across the laboratories. All drug combinations yielded MICs lower than the MICs of any two drugs tested singly, and combinations of AMB, PSC, CSP, and VRC were indifferent (no antagonism) by summations of fractional inhibitory concentration.

Development of a standard reference material for Cr(vi) in contaminated soil

Over the last several decades, considerable contamination by hexavalent chromium has resulted from the land disposal of Chromite Ore Processing Residue (COPR). COPR contains a number of hexavalent chromium-bearing compounds that were produced in high temperature industrial processes. Concern over the carcinogenic potential of this chromium species, and its environmental mobility, has resulted in efforts to remediate these waste sites. To provide support to analytical measurements of hexavalent chromium, a candidate National Institute of Standards and Technology (NIST) Standard Reference Material® (SRM 2701), having a hexavalent chromium content of approximately 500 mg kg−1, has been developed using material collected from a waste site in Hudson County, New Jersey, USA. The collection, processing, preparation and preliminary physico–chemical characterization of the material are discussed. A two-phase multi-laboratory testing study was carried out to provide data on material homogeneity and to assess the stability of the material over the duration of the study. The study was designed to incorporate several United States Environmental Protection Agency (USEPA) determinative methods for hexavalent chromium, including Method 6800 which is based on speciated isotope dilution mass spectrometry (SIDMS), an approach which can account for chromium species inter-conversion during the extraction and measurement sequence.

Multi-laboratory testing of a screening method for world trade center (WTC) collapse dust

The September 11, 2001 attack on the World Trade Center (WTC) covered a large area of downtown New York City with dust and debris. This paper describes the testing of an analytical method designed to evaluate whether sampled dust contains dust that may have originated from the collapse of the WTC. Using dust samples collected from locations affected and not affected (referred to as ‘background’ locations) by the collapse, a scanning electron microscopy (SEM) analysis method was developed to screen for three materials that are believed to be present in large quantities in WTC dusts: slag wool, concrete, and gypsum. An inter-laboratory evaluation of the method was implemented by having eight laboratories analyze a number of ‘blind’ dust samples, consisting of confirmed background dust and confirmed background dust spiked with varying amounts of dust affected by the WTC collapse. The levels of gypsum and concrete in the spiked samples were indistinguishable from the levels in the background samples . Measurements of slag wool in dust demonstrated potential for distinguishing between spiked and background samples in spite of considerable within and between laboratory variability. Slag wool measurements appear to be sufficiently sensitive to distinguish dust spiked with 5% WTC-affected dust from 22 out of 25 background dust samples. Additional development work and inter-laboratory testing of the slag wool component will be necessary to improve the precision and accuracy of the method and reduce inter- and intra-laboratory variability from levels observed in the inter-laboratory evaluation.

Ruggedness testing of quantitative atmospheric pressure ionization mass spectrometry methods: the effect of co‐injected matrix on matrix effects

A number of techniques have been suggested to date for assessing matrix effects on quantitative atmospheric pressure ionization mass spectrometry (API-LC/MS) methods. A newly designed experiment has the aim of efficiently simulating the quantitative behavior of an LC/MS method as a function of the amount of co-injected matrix extract. Two sets of mixtures were prepared in different formats to study matrix effects as a function of analyte or matrix amount. Chromatographic conditions were varied as well, to alter the separation between analyte and co-extractants, and thereby provide different matrix effect conditions for testing the same mixtures. Graphical presentation of the results was used to gain insight into the matrix effect phenomenon. The results suggest that ruggedness for API-LC/MS methods may be defined as the absence of significant variation in results as a function of the amount of co-injected matrix. That is, a non-rugged API-LC/MS method may give consistent results only if a fixed amount of matrix is co-injected on a specific instrument. The results also point to the existence of a specific matrix concentration for the onset of matrix effects, below which these effects are not significant. These issues are important to the US FDA Center for Veterinary Medicine, which has regulatory authority for methods used to monitor for drug residues in food tissues from animals. The ruggedness testing technique suggested here may be an important factor in determining that a method is ready for multi-laboratory testing on multiple instruments.