Nuclear extraction from endometrial tumors for single nuclei sequencing v1

Modified from: Slyper, M. et al. A single-cell and single-nucleus RNA-Seq toolbox for fresh and frozen human tumors. Nat. Med. 2020 26526, 792–802 (2020). A optimized protocol for nuclear extraction from endometrial tumors. Performed with endometrial adenocarcinoma, endometrioid type, FIGO grade 1.

Evaluation of an optimized protocol and Illumina ARTIC V4 primer pool for sequencing of SARS-CoV-2 using COVIDSeq™ and DRAGEN™ COVID Lineage App workflow

Next-Generation Sequencing based genomic surveillance has been widely implemented for identification and tracking of emerging SARS-CoV-2 variants to guide the Public Health response to the COVID-19 pandemic. Amplicon-based assays, such as the Illumina® COVIDSeq™ Test (RUO) and COVIDSeq Assay (RUO), enable scalable sequencing of SARS-CoV-2, leveraging V3 and V4 primer designs from the ARTIC community and DRAGEN™ COVID Lineage App analysis available on Illumina BaseSpace™. We report here a comparison of COVIDSeq performance for SARS-CoV-2 genome reporting using the ARTIC V3 based primer pool (including primers for human control genes) that is provided with the COVIDSeq kit versus the ARTIC V4 based Illumina COVIDSeq V4 primer pool, using an optimized protocol and DRAGEN COVID Lineage App analysis. The data indicates that both primer pools enable robust reporting of SARS-CoV-2 variants. The Illumina COVIDSeq V4 primer pool has superior performance for SARS-CoV-2 genome reporting, particularly in samples with low virus load, and is therefore the recommended primer pool for genomic surveillance of SARS-CoV-2 for research use using COVIDSeq.

SHERRY2: A method for rapid and sensitive single cell RNA-seq

Many single cell RNA-seq applications aim to probe a wide dynamic range of gene expression, but most of them are still challenging to accurately quantify low-aboundance transcripts. Based on our previous finding that Tn5 transposase can directly cut-and-tag DNA/RNA hetero-duplexes, we present SHERRY2, an optimized protocol for sequencing transcriptomes of single cells or single nuclei. SHERRY2 is robust and scalable, and it has higher sensitivity and more uniform coverage in comparison with prevalent scRNA-seq methods. With throughput of a few thousand cells per batch, SHERRY2 can reveal the subtle transcriptomic differences between cells and facilitate important biological discoveries.

Quantitative intracellular retention of delivered RNAs through optimized cell fixation and immuno-staining.

Detection of nucleic acids within sub-cellular compartments is key to understanding their function. Determining the intracellular distribution of nucleic acids requires quantitative retention and estimation of their association with different organelles by immunofluorescence microscopy. This is particularly important for the delivery of nucleic acid therapeutics which depends on endocytic uptake and endosomal escape. However, the current protocols fail to preserve the majority of exogenously delivered nucleic acids in the cytoplasm. To solve this problem, by monitoring Cy5-labeled mRNA delivered to primary human adipocytes via lipid nanoparticles (LNP), we optimized cell fixation, permeabilization and immuno-staining of a number of organelle markers, achieving quantitative retention of mRNA and allowing visualization of levels which escape detection using conventional procedures. The optimized protocol proved effective on exogenously delivered siRNA, miRNA, as well as endogenous miRNA. Our protocol is compatible with RNA probes of single molecule fluorescence in-situ hybridization (smFISH) and molecular beacon, thus demonstrating that it is broadly applicable to study a variety of nucleic acids in cultured cells.

Chicken Immune Cell Assay to Model Adaptive Immune Responses In Vitro

Knowledge about the modes of action of immunomodulating compounds such as pathogens, drugs, or feed additives, e.g., probiotics, gained through controlled but animal-related in vitro systems using primary cultured peripheral blood mononuclear cells (PBMCs) will allow the development of targeted nutrition strategies. Moreover, it could contribute to the prevention of infectious diseases and the usage of antimicrobials, and further promote the health of the animals. However, to our knowledge, a protocol for the isolation of PBMCs with reduced thrombocyte count from chicken blood and subsequent cell culture over several days to assess the effects of immunomodulating compounds is not available. Therefore, we established an optimized protocol for blood sampling and immune cell isolation, culture, and phenotyping for chicken PBMCs. For blood sampling commercial Na–citrate tubes revealed the highest count of vital cells compared to commercial Li–heparin (p < 0.01) and K3EDTA (p < 0.05) tubes. Using combined dextran and ficoll density gradient separation, the thrombocyte count was significantly reduced (p < 0.01) compared to slow-speed centrifugation with subsequent ficoll. For cell culture, the supplementation of RPMI-1640 medium with 10% chicken serum resulted in the lowest relative cell count of thrombocytes compared to fetal calf serum (FCS) (p < 0.05). To validate the ability of the cell culture system to respond to stimuli, concanavalin A (conA) was used as a positive control. The optimized protocol allows the isolation and cultivation of vital PBMCs with reduced thrombocyte count from chicken blood for subsequent investigation of the modes of action of immunomodulating compounds.

Applying Different Chemical Methods to Develop an Efficient Acellular Rat Uterine Tissue Matrix

Purpose: Decellularized uterine scaffold, as a new achievement in tissue engineering, permits recellularization and regeneration of uterine tissues and supports pregnancy in a fashion comparable to the intact uterus. The main purpose of this study was using of different chemical methods to introduce an optimized protocol for decellularization of rat uterus.Method: We decellularized rat uteruses by four different protocols using sodium dodecyl sulfate (SDS) and triton-X100 with different doses and time incubations.We characterized the scaffolds through histopathological staining, DNA quantification, MTT assay, Blood compatibility assay, Field Emission Scanning Electron Microscopy (FESEM), and biomechanical studies.Results: Histology assessment showed that only in protocol 4, cell residues were completely removed. Masson’s trichrome staining demonstrates that in protocol P3 collagen bundles were decreased; however, no damage in the collagen bundles was observed by other protocols. Cell viabilities indirect MTT assays of all protocols were significantly higher than the native samples. The RBC hemolysis percent in the presence of prepared scaffolds from all 4 protocols was less than 2%. The mechanical properties of none of the protocols were significantly different from the native sample. Conclusion: Protocol 4 which used freeze-thawing before using detergent, was introduced as the optimized protocol due to complete removal of cell residue, preservation of the three-dimensional structure, complete removal of detergents, and preservation of the mechanical property of the scaffolds.