Method For Isolation Of Cells Research Articles

A microfluidics-based method for isolation and visualization of cells based on receptor-ligand interactions.

Receptor-ligand binding has been analyzed at the protein level using isothermal titration calorimetry and surface plasmon resonance and at the cellular level using interaction-associated downstream gene induction/suppression. However, no currently available technique can characterize this interaction directly through visualization. In addition, all available assays require a large pool of cells; no assay capable of analyzing receptor-ligand interactions at the single-cell level is publicly available. Here, we describe a new microfluidic chip–based technique for analyzing and visualizing these interactions at the single-cell level. First, a protein is immobilized on a glass slide and a low-flow-rate pump is used to isolate cells that express receptors that bind to the immobilized ligand. Specifically, we demonstrate the efficacy of this technique by immobilizing biotin-conjugated FGL2 on an avidin-coated slide chip and passing a mixture of GFP-labeled wild-type T cells and RFP-labeled FcγRIIB-knockout T cells through the chip. Using automated scanning and counting, we found a large number of GFP+ T cells with binding activity but significantly fewer RFP+ FcγRIIB-knockout T cells. We further isolated T cells expressing a membrane-anchored, tumor-targeted IL-12 based on the receptor’s affinity to vimentin to confirm the versatility of our technique. This protocol allows researchers to isolate receptor-expressing cells in about 4 hours for further downstream processing.

423 Novel method for isolation of small airway epithelial cells by bulk enzymatic digestion

423 Novel method for isolation of small airway epithelial cells by bulk enzymatic digestion

Methods for Isolation of Tumor-Associated Endothelial Cells for Surface Protein Analysis and Sorting by Flowcytometry.

Polychromatic flowcytometry is increasingly used for simultaneously analyzing multiple intracellular and cell-surface proteins on a given cell population. Here we describe a flowcytometry-based method to analyze various proteins on the surface of endothelial cells (which comprise of less than 0.5% of the tumor microenvironment) and concurrently sort the live endothelial cells for the downstream applications such as gene expression by conventional quantitative PCR or by single-cell RNA sequencing.

Aptamer-Based Traceless Multiplexed Cell Isolation Systems.

In both biomedical research and clinical cell therapy manufacturing, there is a need for cell isolation systems that recover purified cells in the absence of any selection agent. Reported traceless cell isolation methods using engineered antigen-binding fragments or aptamers have been limited to processing a single cell type at a time. There remains an unmet need for cell isolation processes that rapidly sort multiple target cell types. Here, we utilized two aptamers along with their designated complementary strands (reversal agents) to tracelessly isolate two cell types from a mixed cell population with one aptamer-labeling step and two sequential cell elution steps with reversal agents. We engineered a CD71-binding aptamer (rvCD71apt) and a reversal agent pair to be used simultaneously with our previously reported traceless purification approach using the CD8 aptamer (rvCD8apt) and its reversal agent. We verified the compatibility of the two aptamer displacement mechanisms by flow cytometry and the feasibility of incorporating rvCD71apt with a magnetic solid state. We then combined rvCD71apt with rvCD8apt to isolate activated CD4+ T cells and resting CD8+ cells by eluting these target cells into separate fractions with orthogonal strand displacements. This is the first demonstration of isolating different cell types using two aptamers and reversal agents at the same time. Potentially, different or more aptamers can be included in this traceless multiplexed isolation system for diverse applications with a shortened operation time and a lower production cost.

Abstract 21 High-Throughput Blood Separation System for CD34+ Cell Isolation

IntroductionResearch into the therapeutic roles and clinical potential of CD34+ cells is growing [Weissman and Shizuru, Blood. 2008;112(9):3543-3553]. Accordingly, advances in cell isolation methods have risen to meet the research demand. Cord blood banks have a unique opportunity to source CD34+ cells because of their relatively high prevalence in cord blood [Dauber et al. Cytotherapy. 2011;13(4):449-458]. However, current isolation systems are not optimized for processing cord blood, and even blood-compatible systems typically require the blood to be processed before use. FerroBio (www.42bio.com) has developed a magnetic separation system that facilitates scalable, high-volume cell isolation from complex biological fluids, such as blood, without pre-processing. This technology is now being adapted for CD34+ cell isolation from cord blood.ObjectiveIn this study, the conditions in which magnetic beads efficiently bind target cells were explored. The objective of this work was to evaluate optimal blood mixing conditions to bring beads into contact with cells in suspension in the blood. This will allow unmodified cord blood units (CBUs) to flow directly into our apparatus.MethodsThe FerroBio separation process is comprised of three simple steps (Figure 1A). Here, conditions of step 1 were explored to maximize target cell recovery and viability. Variables included type of agitation equipment (Figure 1B), temperature, time, and relative air volume in the blood bag. Recovery and viability were measured via flow cytometry and calculated relative to unprocessed blood from the same CBU.ResultsTwo mixing conditions were identified for maximum recovery of CD34+ cells (Figure 1C, blue bars). While not statistically different from each other, the Drum Roller method only requires one piece of standard equipment, is gentler, and can accommodate multiple CBUs simultaneously. No statistical difference in viability was observed in any conditions (90.7% ± 16.3%, n = 9). Increasing incubation time and the relative amount of air in the bag did not increase recovery (not shown).Figure 1. (A): Overview of the FerroBio Magnetic Separation Process, highlighting step (1) in which magnetic beads are mixed within the CBU to bind the target CD34+ cells. (B): Illustrations of the agitation equipment used to mix the CBU during step (1). (C): The resulting CD34+ recovery (1-way ANOVA, P = .0245). Image credit for panel (A): BioRender.DiscussionThe FerroBio separator can streamline CD34+ cell isolation by processing high blood volumes in a fast, closed system with high recovery rates. Additional studies are under way to evaluate the functionality of the isolated CD34+ cells and efficiency of bead removal.

Reassessment of adipocyte technology for cellular agriculture of alternative fat.

Alternative proteins, such as cultivated meat, have recently attracted significant attention as novel and sustainable food. Fat tissue/cell is an important component of meat that makes organoleptic and nutritional contributions. Although adipocyte biology is relatively well investigated, there is limited focus on the specific techniques and strategies to produce cultivated fat from agricultural animals. In the assumed standard workflow, stem/progenitor cell lines are derived from tissues of animals, cultured for expansion, and differentiated into mature adipocytes. Here, we compile information from literature related to cell isolation, growth, differentiation, and analysis from bovine, porcine, chicken, other livestock, and seafood species. A diverse range of tissue sources, cell isolation methods, cell types, growth media, differentiation cocktails, and analytical methods for measuring adipogenic levels were used across species. Based on our analysis, we identify opportunities and challenges in advancing new technology era toward producing "alternative fat" that is suitable for human consumption.

Isolation and Culture of Three Kinds of Umbilical Cord Mesenchymal Stem Cells

Umbilical cord mesenchymal stem cells (UC-MSCs) are an important cell source for regenerative medicine. UC-MSCs can be isolated from the umbilical cord Wharton's jelly, as well as from the umbilical arteries and umbilical vein. They are known as perivascular stem cells obtained from umbilical arteries (UCA-PSCs), perivascular stem cells obtained from the umbilical vein (UCV-PSCs), and mesenchymal stem cells obtained from Wharton's jelly (WJ-MSCs). UCA-PSCs and UCV-PSCs are pericytes derived from perivascular regions that are progenitors of MSCs. Isolation and culture of the three kinds of cells is an important source for studying stem cell transplantation and repair. The present protocol focuses on the isolation and culture of cells through mechanical separation, adherent culture, and cell crawling out. Through this technique, the three different types of stem cells can be derived. Cell surface markers were detected by flow cytometry. The stem cells were detected for multilineage differentiation potential by adipogenic, osteogenic, and neural-like differentiation, which is consistent with the phenotype of MSCs. This experimental protocol expands the source of UC-MSCs. In addition, the cell isolation method provides a basis for further study of regenerative medicine and other applications.

Isolation and short-term culturing of primary lymphatic endothelial cells from collecting lymphatics: A techniques study.

To develop an experimental method for routine isolation and short-term culture of primary lymphatic endothelial cells from specific collecting vessels. Lymphatic endothelial cell tubes (LECTs) were isolated from micro-dissected collecting vessels. LECTs were allowed to attach and grow for ~3 weeks before being passaged. Non-purified cultures were partially characterized by immunofluorescence and RT-PCR at passages 1-2. The method was validated in cultures of primary lymphatic endothelial cells (LECs) from male and female mice. After 1 or 2 passages, >60% of the LECs maintained expression of Prox1. Expression of 22 different genes was assessed using RT-PCR. Prox1, Vegfr3, eNos, Cdh5, Pecam1, Cx43, Cx37, and Cx47, among others, were expressed in these short-term cultured LECs, while Myh11, Cnn1, Desmin, and Cd11b were not detected. Prox1 expression, as determined by western blotting, was similar in cultured LECs from age-matched male and female mice. Confocal imaging of intracellular calcium in cultures of primary LECs from Cdh5-GCaMP8 mice demonstrated that a functional phenotype was maintained, similar to lymphatic endothelial cells in freshly isolated vessels. This method provides an innovative tool for routine isolation and study of primary LECs from specific collecting lymphatic vessels from any mouse, and in fact, from other species.

Novel strategy for primary epithelial cell isolation: Combination of hyaluronidase and collagenase I.

Different strategies for epithelial cell isolation significantly affect the viability and physiological properties of primary cells. Trypsin digestion, a conventional method, causes collateral damage owing to its strong digestive potential. To better preserve the physiological properties of epithelial tissues, we aimed to develop a modified method (hyaluronidase and collagenase I combination) for primary cell isolation. We used conventional and modified methods to compare cell viability, morphology and stemness. Additionally, we investigated the passaging stability of epithelial cells and their capacity for organoid formation. Finally, we compared the two methods for isolating urothelial, oesophageal, lingual, and epidermal epithelial cells. Gingival epithelial cells obtained using the modified method had higher viability, better morphology and stronger stemness than those obtained using the conventional method. Additionally, primary cells obtained using the modified method were stably passaged. Regarding organoid culture, adopting the modified method led to a significant increase in the growth rate and expression of the stem cell markers cytokeratin (CK)-19 and Ki-67. Furthermore, the modified method outperformed the conventional method for isolating urothelial, epidermal, oesophageal and lingual epithelial cells. We demonstrated that the combination of hyaluronidase and collagenase I outperformed trypsin in preserving the physiological properties of primary cells and organoid formation. The modified method could be broadly applied to isolate different types of epithelial cells and facilitate studies on organoids and tissue engineering.

Acoustophoretic Motion of Leishmania spp. Parasites.

The analysis of cell motion in an acoustic field is of interest as it can lead to new methods of cell separation, isolation and manipulation for diagnosis and treatment of diseases. Studies of the motion of different species of Leishmania parasites during exposure to ultrasonic standing waves in a microfluidic device allowed identification of acoustic responses of these parasites in their promastigote and amastigote forms. Both forms exhibited a positive acoustic contrast factor and were driven toward the pressure node established in the center of the channel by the acoustically induced radiation force (FR). Promastigotes experience calculated FR amplitudes one order of magnitude larger than those experienced by amastigotes because of the measured differences in volume. The aggregates formed at the pressure node have distinct shapes and stability conditions, for both promastigotes and amastigotes.

Integration of Single-Cell Transcriptomics With a High Throughput Functional Screening Assay to Resolve Cell Type, Growth Kinetics, and Stemness Heterogeneity Within the Comma-1D Cell Line.

Cell lines are one of the most frequently implemented model systems in life sciences research as they provide reproducible high throughput testing. Differentiation of cell cultures varies by line and, in some cases, can result in functional modifications within a population. Although research is increasingly dependent on these in vitro model systems, the heterogeneity within cell lines has not been thoroughly investigated. Here, we have leveraged high throughput single-cell assays to investigate the Comma-1D mouse cell line that is known to differentiate in culture. Using scRNASeq and custom single-cell phenotype assays, we resolve the clonal heterogeneity within the referenced cell line on the genomic and functional level. We performed a cohesive analysis of the transcriptome of 5,195 sequenced cells, of which 85.3% of the total reads successfully mapped to the mm10-3.0.0 reference genome. Across multiple gene expression analysis pipelines, both luminal and myoepithelial lineages were observed. Deep differential gene expression analysis revealed eight subclusters identified as luminal progenitor, luminal differentiated, myoepithelial differentiated, and fibroblast subpopulations—suggesting functional clustering within each lineage. Gene expression of published mammary stem cell (MaSC) markers Epcam, Cd49f, and Sca-1 was detected across the population, with 116 (2.23%) sequenced cells expressing all three markers. To gain insight into functional heterogeneity, cells with patterned MaSC marker expression were isolated and phenotypically investigated through a custom single-cell high throughput assay. The comparison of growth kinetics demonstrates functional heterogeneity within each cell cluster while also illustrating significant limitations in current cell isolation methods. We outlined the upstream use of our novel automated cell identification platform—to be used prior to single-cell culture—for reduced cell stress and improved rare cell identification and capture. Through compounding single-cell pipelines, we better reveal the heterogeneity within Comma-1D to identify subpopulations with specific functional characteristics.

Efficient Isolation of Lymphocytes and Myogenic Cells from the Tissue of Muscle Regeneration

Isolation of both lymphocytes and myogenic cells from muscle tissue is required for elucidating the cellular and molecular mechanisms of muscle regeneration. Here, we aimed to establish an optimal method obtaining a high yield of lymphocytes during muscle regeneration. After the muscle injury, we observed higher infiltration of lymphocytic cells in the muscle on day 3 after injury. Then, we compared two different white blood cell isolation methods, the Percoll gradient and CD45-magnetic bead methods, to assess the percentage and number of T and B cells. Flow cytometry analysis showed that the CD45-magnetic bead method has a better efficiency in isolating CD4+, CD8+ T cells, and B cells from injured muscle tissues of wild-type and mdx mice than that by the Percoll gradient method. Moreover, we found that the CD45-negative fraction from wild-type and mdx mice includes myogenic cells. In conclusion, we report that the CD45-magnetic bead method is suitable to isolate T and B cells during muscle regeneration with higher purity and yield and can also isolate myogenic cells within the same sample. This method provides a technical basis for further studies on muscle regeneration, involving lymphocytes and muscle cells, with a wide range of clinical applications.

Proof-of-Concept of a Novel Cell Separation Technology Using Magnetic Agarose-Based Beads

The safety of the cells used for Advanced Therapy Medicinal Products is crucial for patients. Reliable methods for the cell purification are very important for the commercialization of those new therapies. With the large production scale envisioned for commercialization, the cell isolation methods need to be efficient, robust, operationally simple and generic while ensuring cell biological functionality and safety. In this study, we used high magnetized magnetic agarose-based beads conjugated with protein A to develop a new method for cell separation. A high separation efficiency of 91% yield and consistent isolation performances were demonstrated using population mixtures of human mesenchymal stem cells and HER2+ SKBR3 cells (80:20, 70:30 and 30:70). Additionally, high robustness against mechanical stress and minimal unspecific binding obtained with the protein A base conjugated magnetic beads were significant advantages in comparison with the same magnetic microparticles where the antibodies were covalently conjugated. This study provided insights on features of large high magnetized microparticles, which is promising for the large-scale application of cell purification.

Isolation and culture methods of human breastmilk stem cells: A systematic review

With the rapid development of cell-based therapy, the source of stem cells derived from non-invasive techniques have been intensively studied for their potential to replace the invasive source of stem cells. One of the alternative sources of stem cells is the cells taken from human breastmilk. Human breastmilk is always readily available, easy to access and can last for an extended period. Unfortunately, the standard protocol to isolate the cells from breastmilk is still not well explained. Our study aimed to investigate three main questions in human breastmilk stem cells: the optimal lactation stage, isolation and culture method, and the characterization of human breastmilk stem cells. We searched in vitro studies that used human breastmilk as a cell source of stem cells and clearly explained the step-by-step procedure. From the initial 457 studies, 15 articles fulfilled the criteria and were further analyzed. The results showed that the stem cells could be taken from breastmilk in any lactation stage and isolated with various techniques to obtain both pluri- and multipotent stem cells. Although breastmilk can be used as an alternative for noninvasive source of stem cell, the results of few study groups were found sometimes contradicting another group, resulting in confusing theory. Therefore, the standard protocol is still needed to tackle the confounding results.

Analysis of High-Throughput Processing Methods for Peripheral Blood Cell Isolation.

Analysis of High-Throughput Processing Methods for Peripheral Blood Cell Isolation.

Comparison of sample preparation methods for rare cell isolation in microfluidic devices.

The analysis of circulating tumor cells (CTCs) is important for cancer diagnosis and prognosis. Microfluidics has been employed for CTC analysis due to its scaling advantages and high performance. However, pre-analytical methods for CTC sample preparation are often combined with microfluidic platforms because a large sample volume is required to detect extremely rare CTCs. Among pre-analytical methods, Ficoll-Paque™, OncoQuick™, and RosetteSep™ are commonly used to separate cells of interest. To compare their performance, we spiked L3.6pl pancreatic cancer cells into healthy blood samples and then employed each technique to prepare blood samples, followed by using a microfluidic platform to capture and detect L3.6pl cells. We found these three methods have similar performance, though the slight edge of RosetteSep™ over Ficoll-Paque™ is statistically significant. We also studied the effects of the tumor cell concentrations on the performance of the frequently used Ficoll-Paque™ method. Furthermore, we examined the repeatability and variability of each pre-analytical technique and the microfluidics-enabled detection. This study will provide researchers and clinicians with comparative data that can influence the choice of sample preparation method, help estimate CTC loss in each pre-analytical method, and correlate the results of clinical studies that employ different techniques.

Optimization of human umbilical cord blood-derived mesenchymal stem cell isolation and culture methods in serum- and xeno-free conditions

BackgroundAlthough umbilical cord blood (UCB) is identified as a source of mesenchymal stem cells (MSCs) with various advantages, the success in cell isolation is volatile. Therefore, it is necessary to optimize methods of cord blood-derived MSC (UCB-MSC) isolation and culture. In this study, we evaluated the efficiency of UCB-MSC isolation and expansion using different commercially available serum- and xeno-free media and investigated the capacity of autologous serum and plasma as a supplement to support cell proliferation. Additionally, we defined the presence of multilineage-differentiating stress-enduring (Muse) cells in the UCB-MSC population. Functions of UCB-MSC in in vitro angiogenesis processes and anti-cancer were also verified.MethodsMononuclear cells were isolated using density gradient separation and cultured in four commercial media kits, as well as four surface coating solutions. UCB-MSCs were characterized and tested on tube formation assay, and co-cultured with SK-MEL cells in a transwell system.ResultsThe results showed that only StemMACS™ MSC Expansion Media is more appropriate to isolate and culture UCB-MSCs. The cells exhibited a high cell proliferation rate, CFU forming capability, MSC surface marker expression, trilineage differentiate potential, and chromosome stability. In addition, the culture conditions with autologous serum coating and autologous plasma supplement enhanced cell growth and colony forming. This cell population contained Muse cells at rate of 0.3%. Moreover, UCB-MSCs could induce the tube formation of human umbilical vein endothelial cells and inhibit more than 50% of SK-MEL cell growth.ConclusionsUCB-MSCs could be high-yield isolated and expanded under serum- and xeno-free conditions by using the StemMACS™ MSC Expansion Media kit. Autologous serum coating and plasma supplement enhanced cell proliferation. These UCB-MSCs had effected the tube formation process and an anti-cancer impact.

Hematopoietic Cell Isolation by Antibody-Free Flow Cytometry in the Zebrafish Embryo.

The zebrafish is a useful model to identify genes functioning in hematopoiesis, owing to high conservation of hematopoiesis. Flow cytometry is widely used to isolate and quantitatively characterize human and mouse hematopoietic cells, often using fluorescently labeled antibodies. However, such analysis is limited in zebrafish due to lack of antibodies that recognize zebrafish hematopoietic cells. We here describe methods for isolation of hematopoietic cells by antibody-free flow cytometry in the zebrafish embryo. Hematopoietic stem cells (HSCs) are specified from a specific subset of vascular endothelial cells, the hemogenic endothelial cell (HEC), by a high level of Notch signaling. In combination with a Notch reporter line (Tp1:GFP) and a vascular specific line (fli1a:dsRed), HECs can be isolated as Tp1:GFPhigh fli1a:dsRed+ cells at 20-22hours post-fertilization (hpf). Zebrafish erythrocytes can be purified using 1,5-bis{[2-(dimethylamino)ethyl]amino}-4, 8-dihydroxyanthracene-9,10-dione (DRAQ5), a DNA-staining fluorescent dye, and gata1:dsRed (erythroid marker line). DRAQ5high dsRed+ cells are morphologically erythrocyte-like, hemoglobin-stained positive, and express erythropoiesis-related genes. Zebrafish neutrophils can be also isolated using the lectin Phaseolus vulgaris erythroagglutinin (PHA-E) and DRAQ5. PHA-Elow DRAQ5low cells have myeloperoxidase activity, are Sudan Black B-positive, and express neutrophil-related genes. These methods will help to perform genetical and functional assays for various types of hematopoietic cells in zebrafish embryos.

Isolation of Porcine Bone Marrow Cells and Generation of Recombinant African Swine Fever Viruses.

Genetic manipulation of ASFV has been increasingly used not only for the development of live attenuated vaccines but also as an indispensable tool to further our understanding of the virus-host interactions. Here we present methods for isolation of porcine bone marrow cells and purification of recombinant ASFV using both chromogenic and fluorescent reporters. We also describe in detail a newly developed method to purify genetically modified ASFV using fluorescence-activated cell sorting (FACS).

A Rapid Adaptable Method for Isolation of Endothelial Cells from Human Adipose Tissue.

Human adipose tissue is the largest endocrine organ and plays a role in whole-body metabolism. Dysfunction of this tissue is involved in multiple diseases, such as obesity, diabetes, and cardiovascular disease. An important factor in maintaining healthy adipose tissue is ensuring correct functioning of the blood vessels in this highly vascularized tissue. The endothelial cells (ECs) which line blood vessels show remarkable heterogeneity in structure and function in physiological and pathological conditions. While multiple studies have been performed to characterize ECs in different organs, the endothelium of adipose tissue remains poorly characterized. One of the significant challenges in working with adipose tissue is the separation and isolation of single viable cells, including ECs. This chapter describes a reliable and flexible approach for the isolation of adipose ECs that could be used for various analysis, including single-cell RNA sequencing, in vitro culture, and downstream applications.