A robust primary immune response has been correlated with the precursor number of antigen-specific T cells, as identified using peptide MHCII tetramers. However, these tetramers identify only the highest-affinity T cells. Here we show the entire CD4+ T-cell repertoire, inclusive of low-affinity T cells missed by tetramers, using a T-cell receptor (TCR) signalling reporter and micropipette assay...

Legislation enacted worldwide to regulate the presence of genetically modified organisms (GMOs) in crops, foods and ingredients, necessitated the development of reliable and sensitive methods for GMO detection. In this article, protein- and DNA-based methods employing western blots, enzyme-linked immunosorbant assay, lateral flow strips, Southern blots, qualitative-, quantitative-, real-time- a...

Abstract Objective The objective of this study is to validate C-Reactive Protein (CRP) measurement in Non-Human Primate (NHP) serum using the ADVIA 1800 analyzer. Methods CRP was validated NHP Validation testing included intra-assay precision, inter-assay accuracy, linearity dilution, limit quantitation (LOQ), detection (LOD), reference interval, carry-over, correlation, and stability. Samples ...

In the first paper of this series (1), we described a limiting dilution assay designed for the determination of any precursor T cell whose effector function can be determined in vitro. For this assay, normal T ceils are used that are polyclonally activated in bulk cuhure with concanavalin A (Con A) 1 and thereafter expanded by limiting dilution in the presence of T cell growth factor (TCGF). Th...

A radioisotope dilution assay for vitamin B12, using hemoglobin-coated charcoal, was modified in several respects, the most prominent of which was the use of cyanide extraction of sera. With these modifications, the B12 levels were significantly higher in sera from normal subjects and patients with folate deficiency, whereas sera from patients with pernicious anemia and other B12-deficient stat...

cd34 is a type i membrane protein with a molecular mass of approximately 110 kda. this antigen is associated with human hematopoietic progenitor cells and is a differentiation stage-specific leukocyte antigen. in this study we have generated and characterized monoclonal antibodies (mabs) directed against a cd34 marker. mice were immunized with two keyhole lympet hemocyanin (klh)-conjugated cd34...

In experiments on the accumulation and elimination of virus particles by Pacific oysters (Crassostrea gigas), an Escherichia coli C2 bacteriophage was used as a virus model. It became necessary to quantitate low concentrations of phage present in samples of seawater, oyster shell liquor, and oyster meats and feces. The agar overlay phage plaque assay is subject to the same limitations with rega...

Introduction. The antigen complex of opportunistic pathogenic bacteria (ACOPB) has a protective effect against avian influenza viruses, herpes virus type 2, and other viruses that cause acute respiratory viral infections. In the context COVID-19 pandemic, an important task is to find out whether ACOPB SARS-CoV-2.
 purpose study was evaluate in vitro virus-inhibitory activity Dubrovka labor...

The plate-dilution frequency technique described facilitates simultaneous enumeration of a wide range of physiologically different microorganisms in complex systems with a precision comparable to dilution tube (most probable number) methods. Replicate microsamples are inoculated from each member of a dilution series onto areas delineated on plates of prepoured solid media; the plates are incuba...

A radioisotope dilution assay for vitamin B12, using hemoglobin-coated charcoal, was modified in several respects, the most prominent of which was the use of cyanide extraction of sera. With these modifications, the B12 levels were significantly higher in sera from normal subjects and patients with folate deficiency, whereas sera from patients with pernicious anemia and other B12-deficient stat...