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The demand for commercially available human breast milk has significantly increased in recent years. For various reasons, a significant amount of commercially available human breast milk is being adulterated with other types of milk. This fraudulent practice poses a threat to consumers' health due to potential adulterants such as cow milk, which may put the infant at risk due to intolerance or allergy. A direct sandwich anti-bovine IgG ELISA has been developed for the sensitive and specific detection of cow milk in adulterated human breast milk. This assay uses polyclonal anti-bovine IgG antibody as a capture antibody and monoclonal anti-bovine IgG-alkaline phosphatase antibody as a detection antibody. Once optimized, the assay was found to be highly sensitive, and specific to bovine IgG. The assay had no significant cross-reaction with human breast milk, indicating that it was highly specific. The anti-bovine IgG ELISA was able to detect the presence of cow milk in adulterated human breast milk with a detection limit of 0.001% cow milk. The developed assay was highly reproducible (coefficient of variation <10%). The developed direct sandwich anti-bovine IgG ELISA is simple, reliable, and reproducible, making it an ideal test for this purpose., (The Authors. Published by Elsevier Inc. and Fass Inc. on behalf of the American Dairy Science Association®. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/).)

Genetics experiments have identified six mutations located in the subdomain IA (A17V, R23H, G32D, G32S, R34K, V372I) of Ssa1 that influence propagation of the yeast [PSI + ] prion. However, the underlining molecular mechanisms of these mutations are still unclear. The six mutation sites are present in the IA subdomain of the nucleotide-binding domain (NBD). The ATPase subdomain IA is a critical mediator of inter-domain allostery in Hsp70 molecular chaperones, so the mutation and changes in this subdomain may influence the function of the substrate-binding domain. In addition, ADP release is a rate-limiting step of the ATPase cycle and dysregulation of the ATPase cycle influences the propagation of the yeast [PSI + ] prion. In this work, steered molecular dynamics (SMD) simulations were performed to explore the interaction between ADP and NBD. Results suggest that during the SMD simulations, hydrophobic interactions are predominant and variations in the binding state of ADP within the mutants is a potential reason for in vivo effects on yeast [PSI + ] prion propagation. Additionally, we identify the primary residues in the ATPase domain that directly constitute the main hydrophobic interaction network and directly influence the ADP interaction state with the NBD of Ssa1. Furthermore, this in silico analysis reaffirms the importance of previously experimentally-determined residues in the Hsp70 ATPase domain involved in ADP binding and also identifies new residues potentially involved in this process.

The detection and confirmation of bloodstains as being human in origin is important in crime scene investigations. There are a number of blood detection methods currently available. The aim of this work was to develop an assay capable of detecting the presence of human blood from both liquid blood samples and dried bloodstains. A simple, direct competitive ELISA was developed utilising a polyclonal antibody against human IgG. Once optimised, the ELISA was found to be specific for human IgG, with no cross-reaction observed with pig, sheep, cow, goat, horse and rabbit IgG. The assay was also found to be sensitive, with a detection limit of 0.1 microg/mL. This compares favourably with leading blood detection methods. The assay was able to confirm the presence of human blood in blood mixtures, in stains on a variety of surfaces and also gave positive results with bloodstains that were up to 1 year old. The assay was simple to use, rapid and highly reproducible. The ELISA performance makes it suitable for development as a kit to rival currently used methods for the routine detection of human blood at crime scenes. Further applications of the anti-human IgG antibody are reported, including immunodot assays and a sandwich ELISA format. The methods described here are simple, reliable assays for the identification of human blood and are presented as viable alternatives to existing techniques for blood detection.