Quantitative and Standardized Pseudovirus Neutralization Assay for COVID-19.

COVID-19 is a global pandemic caused by the highly infectious SARS-CoV-2 virus. Efforts to combat SARS-CoV-2 infection include mass vaccination and development of monoclonal and convalescent plasma therapeutics that require precise measurements of correlative, functional neutralizing antibodies that prevent virus infection. Developing rapid, safe, easy-to-use, and high-quality neutralization assays are essential for the success of the massive effort.

Monoclonal Antibodies as SARS-CoV-2 Serology Standards: Experimental Validation and Broader Implications for Correlates of Protection.

COVID-19 has highlighted challenges in the measurement quality and comparability of serological binding and neutralization assays. Due to many different assay formats and reagents, these measurements are known to be highly variable with large uncertainties. The development of the WHO international standard (WHO IS) and other pool standards have facilitated assay comparability through normalization to a common material but does not provide assay harmonization nor uncertainty quantification.

Quantitation and integrity evaluation of RNA genome in lentiviral vectors by direct reverse transcription-droplet digital PCR (direct RT-ddPCR).

Lentiviral vectors (LV) have proven to be powerful tools for stable gene delivery in both dividing and non-dividing cells. Approval of these LVs for use in clinical applications has been achieved by improvements in LV design. Critically important characteristics concerning quality control are LV titer quantification and the detection of impurities.

Development of a Cell-Based SARS-CoV-2 Pseudovirus Neutralization Assay Using Imaging and Flow Cytometry Analysis.

COVID-19 is an ongoing, global pandemic caused by the novel, highly infectious SARS-CoV-2 virus. Efforts to mitigate the effects of SARS-CoV-2, such as mass vaccination and development of monoclonal therapeutics, require precise measurements of correlative, functional neutralizing antibodies that block virus infection. The development of rapid, safe, and easy-to-use neutralization assays is essential for faster diagnosis and treatment.

A Sensitive and Controlled Data-Independent Acquisition Method for Proteomic Analysis of Cell Therapies.

Mass spectrometry (MS)-based proteomic measurements are uniquely poised to impact the development of cell and gene therapies. With the adoption of rigorous instrumental performance qualifications (PQs), large-scale proteomics can move from a research to a manufacturing control tool. Especially suited, data-independent acquisition (DIA) approaches have distinctive qualities to extend multiattribute method (MAM) principles to characterize the proteome of cell therapies.

Practical application of microsphere samples for benchmarking a quantitative phase imaging system.

Quantitative phase imaging (QPI) provides an approach for monitoring the dry mass of individual cells by measuring the optical pathlength of visible light as it passes through cells. A distinct advantage of QPI is that the measurements result in optical path length quantities that are, in principle, instrument independent. Reference materials that induce a well-defined optical pathlength shift and are compatible with QPI imaging systems will be valuable in assuring the accuracy of such measurements on different instruments.

Quantifying proliferative and surface marker heterogeneity in colony-founding connective tissue progenitors and their progeny using time-lapse microscopy.

Connective tissue progenitors (CTPs) are defined as the heterogeneous population of tissue-resident stem and progenitor cells that are capable of proliferating and differentiating into connective tissue phenotypes. The prevalence and variation in clonal progeny of CTPs can be characterized using a colony formation assay. However, colony assays do not directly assess the characteristics of the colony-founding CTP.

Integrated Colony Imaging, Analysis, and Selection Device for Regenerative Medicine.

Stem and progenitor cells derived from human tissues are being developed as cell sources for cell-based assays and therapies. However, tissue-derived stem and progenitor cells are heterogeneous. Differences in observed clones of stem cells likely reflect important aspects of the underlying state of the source cells, as well as future potency for cell therapies.