{"id":4030,"date":"2025-12-10T16:26:26","date_gmt":"2025-12-10T19:26:26","guid":{"rendered":"https:\/\/desertking.com\/?p=4030"},"modified":"2025-12-10T16:26:26","modified_gmt":"2025-12-10T19:26:26","slug":"detecting-free-qs21-rbc-assay","status":"publish","type":"post","link":"https:\/\/desertking.com\/es\/detecting-free-qs21-rbc-assay\/","title":{"rendered":"Komla, E., et al. Red blood cells as probes for determining free QS21 in liposomal adjuvant formulations to support product safety and stability. Anal Methods, 2025 Nov 20, 17(45):9162-9170.\u00a0"},"content":{"rendered":"<h2><span style=\"font-weight: 400;\">Komla, E., et al. Red blood cells as probes for determining free QS21 in liposomal adjuvant formulations to support product safety and stability. <\/span><i><span style=\"font-weight: 400;\">Anal Methods<\/span><\/i><span style=\"font-weight: 400;\">, 2025 Nov 20, 17(45):9162-9170.\u00a0 PMID: 41196220<\/span><\/h2>\n<ul>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The goal of this study was to develop and validate a straightforward, reliable cell-based assay utilizing human red blood cells to detect and quantify free QS-21 in liposomal vaccine formulations, thereby supporting product safety and stability assessments. QS-21, a potent adjuvant used in various licensed vaccines, exhibits inherent toxicity and hemolytic properties when free. To mitigate these issues, QS-21 is incorporated into lipid-based matrices such as liposomes, which act as QS-21 sinks to suppress its adverse effects. However, ensuring the absence of free QS-21 in these formulations is critical for safety, necessitating robust analytical methods to distinguish between bound and unbound QS-21. This background underscores the importance of developing a sensitive, specific, and accessible assay to monitor free QS-21, ultimately aiming to enhance vaccine safety and quality control during manufacturing, release, and stability studies.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The developed hemolysis-based assay effectively detected and quantified free QS-21 in liposomal vaccine formulations with good specificity, accuracy, and precision, exhibiting a quadratic relationship between hemolytic activity and free QS-21 concentration (R^2 ranging from 0.91 to 0.99). The method&#8217;s sensitivity was in the micromolar range, with a lower limit of quantitation around 25 mg\/mL. Validation studies across multiple blood donors showed consistent performance, and the assay successfully monitored free QS-21 levels in multiple batches of the ALFQ vaccine, revealing minimal to no detectable free QS-21. It indicated formulation stability and batch-to-batch consistency. Additionally, the assay could detect QS-21 leakage during long-term storage, providing a useful tool to ensure product safety and stability during manufacturing and storage.<\/span><\/li>\n<li style=\"font-weight: 400;\" aria-level=\"1\"><span style=\"font-weight: 400;\">The assay&#8217;s reliance on human blood donors introduces variability due to differences in donor sensitivity, requiring careful donor selection to ensure consistent results. Additionally, the method&#8217;s sensitivity has a lower limit of approximately 25 mg\/mL, which may not detect very low levels of free QS-21 below this threshold. The quadratic relationship between hemolytic activity and QS-21 concentration, while robust within the tested range, may complicate quantitation at concentrations approaching the assay&#8217;s detection limits. Future work could focus on enhancing assay sensitivity to detect lower QS-21 levels, possibly by optimizing RBC concentration or detection methods. Developing standardized donor panels or artificial RBC mimetics might reduce variability and improve consistency. Expanding the assay&#8217;s applicability to other liposomal adjuvants or vaccine formulations and validating it across different laboratories would strengthen its utility. Additionally, integrating the assay into a broader stability-indicating testing panel could further support product development and regulatory approval processes.<\/span><\/li>\n<\/ul>\n<p><span style=\"font-weight: 400;\">Click <\/span><a href=\"https:\/\/pubmed.ncbi.nlm.nih.gov\/41196220\/\" rel=\"nofollow noopener\" target=\"_blank\"><span style=\"font-weight: 400;\">here<\/span><\/a><span style=\"font-weight: 400;\"> to access the full scientific paper.\u00a0<\/span><\/p>\n<p>&nbsp;<\/p>\n<p><span style=\"font-weight: 400;\">[arrow_forms id=&#8217;3298&#8242;]<\/span><\/p>\n","protected":false},"excerpt":{"rendered":"<p>Komla, E., et al. Red blood cells as probes for determining free QS21 in liposomal adjuvant formulations to support product safety and stability. Anal Methods, 2025 Nov 20, 17(45):9162-9170.\u00a0 PMID: 41196220 The goal of this study was to develop and validate a straightforward, reliable cell-based assay utilizing human red blood cells to detect and quantify [&hellip;]<\/p>\n","protected":false},"author":16,"featured_media":4032,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"rs_blank_template":"","rs_page_bg_color":"","slide_template_v7":"","footnotes":""},"categories":[46],"tags":[],"class_list":["post-4030","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-texto-cientifico"],"_links":{"self":[{"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/posts\/4030","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/users\/16"}],"replies":[{"embeddable":true,"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/comments?post=4030"}],"version-history":[{"count":0,"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/posts\/4030\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/media\/4032"}],"wp:attachment":[{"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/media?parent=4030"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/categories?post=4030"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/desertking.com\/es\/wp-json\/wp\/v2\/tags?post=4030"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}