LGC Group, formerly the Laboratory of the Government Chemist, is an international life sciences measurement and tools company, which also provides the role and duties of the UK Government Chemist, a statutory role and adviser to the government. LGC also hosts the UK's National Measurement Laboratory (NML) for chemical and bio-measurement, which performs measurements for diagnostics, advanced therapeutics, safety and security, among others.
The ability to determine the identity of equine samples would be highly advantageous in cases of ambiguous sample source, as individual-specific controls for gene editing detection, or forensic examination of suspect biological materials in potential doping cases. To this end, a SNP-PCR sequencing-based panel comprising 93 markers in one reaction was designed and investigated for use in Thoroughbred horses. Marker amplification performance and discriminating power were calculated against a population survey of 264 Thoroughbred whole blood samples from routine doping testing. The sensitivity of the SNP panel was tested on a dilution series and on a variety of matrices, including different types of blood specimen, hair and faeces. No genotyping errors due to allelic dropout were detected down to a starting concentration of 0.25 ng/μL in the dilution series, with both EDTA and lithium heparin anticoagulants performing comparably. Forensic 'crime scene' samples, such as blood on a blood tube label, also performed strongly, although others were more variable due to low DNA concentrations. A mock case of 10 'suspects' and one test blood sample was performed blind by the analyst who correctly identified the source of the sample.
Prohibited gene editing in horses (either in embryos or via cell culture and cloning) can result in both desired and undesired outcomes. If left undetected, changes can proliferate within the population in subsequent generations, posing a major threat to welfare and breed integrity.
Reference and quality control materials with comparable physicochemical properties to nanoplastic contaminants present in environmental and food nanoplastics are currently lacking. Here we report a nanoplastic polypropylene material prepared using a top-down approach involving mechanical fragmentation of larger plastics. The material was found to be homogeneous and stable in suspension and has been characterised for average particle size, size distribution range, particle number concentration, polypropylene mass fraction and inorganic impurity content using a wide range of analytical methods, including AF4, cFFF, PTA, (MA)DLS, MALS, SEM, AFM, TEM, STEM, EDS, Raman, ICP-MS and pyGC-MS. The material was found to have a broad size distribution, ranging from 50 nm to over 200 nm, with the average particle size value dependent on the technique used to determine it. Particle number concentration ranged from 1.7-2.4 x 1010 g-1, according to PTA. Spectroscopy techniques confirmed that the material was polypropylene, with evidence of aging due to an increased level of oxidation. The measured mass fraction was found to depend on the marker used and ranged between 3 and 5 mu g g-1. Inorganic impurities such as Si, Al, Mg, K, Na, S, Fe, Cl and Ca were also identified at ng g-1 levels. Comparability and complementarity across the measurement methods and techniques is also discussed.
Measurement of food allergen protein concentrations against thresholds can improve allergen risk management and precautionary allergen labelling. Such measurement suffers well known problems which could be ameliorated by well characterised reference materials (RMs) providing meaningful information for risk assessors. We investigated the preparation and characterisation of the first consensus informed industrially and clinically relevant multi-allergen matrix RM kit for five priority allergens. It is a medium analytical difficulty processed food chocolate paste matrix (a) devoid of allergens, and (b) incurred with five allergens at the clinically relevant concentration of 10 mg kg(-1) expressed as protein. The allergen raw materials: hens' egg white powder, skimmed cows' milk powder, almond powder (full fat), hazelnut powder (partially defatted), and walnut powder (partially defatted), are also available as RMs. The preparation, gravimetric traceability to the SI, homogeneity, and stability were found to be fit-for-purpose and the RMs are now available to the analytical community.
