High-throughput single-cell sorting by stimulated Raman-activated cell ejection.

Single-cell sorting is essential to explore cellular heterogeneity in biology and medicine. Recently developed Raman-activated cell sorting (RACS) circumvents the limitations of fluorescence-activated cell sorting, such as the cytotoxicity of labels. However, the sorting throughputs of all forms of RACS are limited by the intrinsically small cross-section of spontaneous Raman scattering. Here, we report a stimulated Raman-activated cell ejection (S-RACE) platform that enables high-throughput single-cell sorting based on high-resolution multi-channel stimulated Raman chemical imaging, in situ image decomposition, and laser-induced cell ejection. The performance of this platform was illustrated by sorting a mixture of 1 µm polymer beads, where 95% yield, 98% purity, and 14 events per second throughput were achieved. Notably, our platform allows live cell ejection, allowing for the growth of single colonies of bacteria and fungi after sorting. To further illustrate the chemical selectivity, lipid-rich Rhodotorula glutinis cells were successfully sorted from a mixture with Saccharomyces cerevisiae, confirmed by downstream quantitative PCR. Furthermore, by integrating a closed-loop feedback control circuit into the system, we realized real-time single-cell imaging and sorting, and applied this method to precisely eject regions of interest from a rat brain tissue section. The reported S-RACE platform opens exciting opportunities for a wide range of single-cell applications in biology and medicine.

Isolation, Purification, and Culture of Embryonic Melanoblasts from Green Fluorescent Protein-expressing Reporter Mice.

In this article, we provide a method to isolate embryonic melanoblasts from reporter mouse strains. The mice from which these cells are isolated are bred into the ROSA26mT/mG reporter background, which results in green fluorescent protein (GFP) expression in the targeted melanoblast population. These cells are isolated and purified by fluorescence-activated cell sorting using GFP fluorescence. We also provide a method to culture the purified melanoblasts for further analysis. This method yields > 99% purity melanoblasts specifically targeted, and can be used for a variety of studies, including gene expression, clonogenic experiments, and biological assays, such as viability, capacity for directional migration, or differentiation into melanin-producing melanocytic cells.

Research on fungal culturomics based on different universal media / 中国热带医学

@#Abstract: Objective To screen out a more universally applicable culture medium for the isolation and culturing of pathogenic fungi through comparing the performance of various universal fungal culture media, to optimize the fungal culturomics technique, and to better apply it to the culturomics research of pathogenic fungi. Methods Multiple common fungal culture media Sabouraud dextrose agar (SDA), potato dextrose agar (PDA), modified Dixon (mDixon), modified LeemingNotman agar (MLNA), etc., and a new pan-fungal medium (PF) were used to culture 40 strains of common pathogenic fungi to determine the growth states of strains under different conditions. Based on that, PF, SDA, PDA, mDixon and MLNA, a total of 5 culture media, were used to isolate and culture a simulated sample (suspension of Candida albicans and Aspergillus fumigatus), 10 human samples (4 fecal samples and 6 vaginal secretion samples) and 3 environmental samples. Results The positive growth rates of 40 strains of pathogenic fungi in the 7 media were as follows: PDA 95.0% (38/40), SDA 95.0% (38/40), BHI 95.0% (38/40), YPD 90.0% (36/40), mDixon 95.0% (38/40), MLNA 87.5% (35/40), PF 100.0% (40/40). For the simulated samples, PF could effectively promote the self-limited growth of filamentous fungi, performing better in isolation and culture. For the human samples and environmental samples, PF showed the same versatility as SDA and PDA. Conclusions In the isolation and culturing of pathogenic fungi, PF medium can effectively isolate and culture most fungal species. Meanwhile, PF can make the fast-growing fungi show self-limited growth and clear edges, and not easy to cross-contamination, which indicates it is conducive to the isolation and identification of single colonies. PF medium outperforms other common media in isolating strains from unknown samples in culturomics, which illustrates PF medium can be effectively used for the study of fungal culturomics.

A Tetragenococcus halophilus human gut isolate.

Tetragenococcus halophilus (T. halophilus) is a facultative anaerobic, coccus-shaped halophilic lactic acid-producing bacterium previously detected and cultured in various salty foods and credited for beneficial effects on human health. In this study, we investigated the presence of T. halophilus in human samples using a polyphasic approach including scanning electron microscopy, molecular biology methods and microbial culture. This unique investigation yielded the unprecedented presence of T. halophilus in human feces samples, thus enriching the repertoire of halophilic microorganisms colonizing the human gastrointestinal tract with the isolation and culture of T. halophilus for the first time in humans. Using the E-test strips, the MIC was assessed for T. halophilus strain CSURQ6002: rifampicin (MIC at 0.002 µg/mL), benzylpenicillin (MIC at 0.094 µg/mL), amoxicillin (MIC at 0.5 µg/mL), erythromycin (MIC at 2 µg/mL), clindamycin (MIC at 4 µg/mL), and vancomycin (MIC at 8 µg/mL). However, this strain showed a MIC up to 256 µg/mL for ciprofloxacin, fosfomycin, doxycyclin, imipenem, and colistin. In-silico profiling derived from whole genome sequencing (NCBI accession number: PRJNA780809), was confirmed. This discovery suggested that T. halophilus was part of the human digestive microbiota and that its potential role on human health should be considered.

Isolation and Culture of Single Microbial Cells by Laser Ejection Sorting Technology.

Single-cell isolation and cultivation play an important role in studying physiology, gene expression, and functions of microorganisms. A series of single-cell isolation technologies have been developed, among which single-cell ejection technology is one of the most promising. Single-cell ejection technology has applied laser-induced forward transfer (LIFT) techniques to isolate bacteria, but the viability (or recovery rate) of cells after sorting has not been clarified in current research. In this work, to keep the cells alive as long as possible, we propose a three-layer LIFT system (top layer, 25-nm aluminum film; second layer, 3 µm agar media; third layer, liquid containing bacteria) for the isolation and cultivation of single Gram-negative (Escherichia coli), Gram-positive (Lactobacillus rhamnosus GG [LGG]), and eukaryotic (Saccharomyces cerevisiae) microorganisms. The experiment results showed that the average survival rates for ejected pure single cells were 63% for Saccharomyces cerevisiae, 22% for E. coli DH5α, and 74% for LGG. In addition, we successfully isolated and cultured the green fluorescent protein (GFP)-expressing E. coli JM109 from a mixture containing complex communities of soil bacteria by fluorescence signal. The average survival rate of E. coli JM109 was demonstrated to be 25.3%. In this study, the isolated and cultured single colonies were further confirmed by colony PCR and sequencing. Such precise sorting and cultivation techniques of live single microbial cells could be coupled with other microscopic approaches to isolate single microorganisms with specific functions, revealing their roles in the natural community. IMPORTANCE We developed a laser-induced forward transfer (LIFT) technology to accurately isolate single live microbial cells. The cultivation recovery rates of the ejected single cells were 63% for Saccharomyces cerevisiae, 22% for E. coli DH5α, and 74% for Lactobacillus rhamnosus GG (LGG). With coupled LIFT with a fluorescence microscope, we demonstrated that single cells of GFP-expressing E. coli JM109 were sorted according to fluorescence signal from a complex community of soil bacteria and subsequently cultured with 25% cultivation recovery rate. This single-cell live sorting technology could isolate single microbes with specific functions, revealing their roles in the natural community.

Characterization, isolation, and culture of spermatogonial stem cells in Macaca fascicularis.

Spermatogonial stem cells (SSCs) have great applications in both reproductive and regenerative medicine. Primates including monkeys are very similar to humans with regard to physiology and pathology. Nevertheless, little is known about the isolation, the characteristics, and the culture of primate SSCs. This study was designed to identify, isolate, and culture monkey SSCs. Immunocytochemistry was used to identify markers for monkey SSCs. Glial cell line-derived neurotrophic factor family receptor alpha-1 (GFRA1)-enriched spermatogonia were isolated from monkeys, namely Macaca fascicularis (M. fascicularis), by two-step enzymatic digestion and magnetic-activated cell sorting, and they were cultured on precoated plates in the conditioned medium. Reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry, and RNA sequencing were used to compare phenotype and transcriptomes in GFRA1-enriched spermatogonia between 0 day and 14 days of culture, and xenotransplantation was performed to evaluate the function of GFRA1-enriched spermatogonia. SSCs shared some phenotypes with rodent and human SSCs. GFRA1-enriched spermatogonia with high purity and viability were isolated from M. fascicularis testes. The freshly isolated cells expressed numerous markers for rodent SSCs, and they were cultured for 14 days. The expression of numerous SSC markers was maintained during the cultivation of GFRA1-enriched spermatogonia. RNA sequencing reflected a 97.3% similarity in global gene profiles between 0 day and 14 days of culture. The xenotransplantation assay indicated that the GFRA1-enriched spermatogonia formed colonies and proliferated in vivo in the recipient c-KitW/W (W) mutant mice. Collectively, GFRA1-enriched spermatogonia are monkey SSCs phenotypically both in vitro and in vivo. This study suggests that monkey might provide an alternative to human SSCs for basic research and application in human diseases.

Characterization, isolation, and culture of spermatogonial stem cells in / 亚洲男科学杂志(英文版)

Spermatogonial stem cells (SSCs) have great applications in both reproductive and regenerative medicine. Primates including monkeys are very similar to humans with regard to physiology and pathology. Nevertheless, little is known about the isolation, the characteristics, and the culture of primate SSCs. This study was designed to identify, isolate, and culture monkey SSCs. Immunocytochemistry was used to identify markers for monkey SSCs. Glial cell line-derived neurotrophic factor family receptor alpha-1 (GFRA1)-enriched spermatogonia were isolated from monkeys, namely Macaca fascicularis (M. fascicularis), by two-step enzymatic digestion and magnetic-activated cell sorting, and they were cultured on precoated plates in the conditioned medium. Reverse transcription-polymerase chain reaction (RT-PCR), immunocytochemistry, and RNA sequencing were used to compare phenotype and transcriptomes in GFRA1-enriched spermatogonia between 0 day and 14 days of culture, and xenotransplantation was performed to evaluate the function of GFRA1-enriched spermatogonia. SSCs shared some phenotypes with rodent and human SSCs. GFRA1-enriched spermatogonia with high purity and viability were isolated from M. fascicularis testes. The freshly isolated cells expressed numerous markers for rodent SSCs, and they were cultured for 14 days. The expression of numerous SSC markers was maintained during the cultivation of GFRA1-enriched spermatogonia. RNA sequencing reflected a 97.3% similarity in global gene profiles between 0 day and 14 days of culture. The xenotransplantation assay indicated that the GFRA1-enriched spermatogonia formed colonies and proliferated in vivo in the recipient c-Kit

Isolation and Characterization of Cardiac Progenitor Cells.

Cardiac progenitor cells (CPCs) are gaining interest as a therapeutic option for the treatment of the heart. Due to the limited pool of CPCs residing in the heart, it is essential to isolate and expand the CPCs in vitro. Here we describe the protocol for isolation and culture of the heterogeneous population of CPCs from right atrial appendage and left ventricular tissue collected from patients undergoing on-pump coronary artery bypass graft surgery for the treatment of ischemic heart disease. Our protocol is developed to simultaneously isolate, culture, and characterize the CPCs from both atrial and ventricular tissues. We also describe the protocol for flow cytometry and immunohistochemical characterization of the isolated CPCs.

Characterization of isolated rat caput epididymal primary epithelial cells: A molecular biology approach.

Sperm maturation in the epididymis is a tightly regulated process which involves secretion and addition of a variety of proteins onto the sperm surface. The molecular mechanisms governing these processes has gained interest in the last decade. In vitro model systems to study the role of epididymal proteins in sperm maturation and other physiological process are very important. Isolation of epididymal cells, culture of epididymal explants and generation of immortalized cells were standardized to be used as in vitro models to study epididymal function. However, isolation and maintenance of primary cultures of epididymal epithelial cells seems to be the best option because of its closeness to the in vivo conditions. Though structural and morphological characterization of primary cultures of epididymal epithelial cells were carried out, the same were not conducted at the molecular level. In this study, we isolated adult rat epididymal primary epithelial cells (EPECs) and characterized them for their purity and cell specific expression of molecular markers. Isolated EPECs exhibited normal cell morphology and were sub cultured and maintained up to 3 weeks. EPECs expressed the epithelial marker, E-cadherin and their purity was estimated to be 73% using flow cytometry. EPECs abundantly expressed CRISP1, Urp1a, Pate-F, Crisp1, Ar and Spag11e, markers of epididymal cells and were negative for Urp1b and Pate, markers negative for epididymis. Results of our study provide a systematic characterization of EPECs at the molecular level and thus a refinement to the previously reported characterization methods.

Isolation and Culture of Single Myofiber and Immunostaining of Satellite Cells from Adult C57BL/6J Mice.

Myofiber isolation followed with ex vivo culture could recapitulate and visualize satellite cells (SCs) activation, proliferation, and differentiation. This approach could be taken to understand the physiology of satellite cells and the molecular mechanism of regulatory factors, in terms of the involvement of intrinsic factors over SCs quiescence, activation, proliferation and differentiation. Single myofiber culture has several advantages that the traditional approach such as FASC and cryosection could not compete with. For example, myofiber isolation and culture could be used to observe SCs activation, proliferation and differentiation at a continuous manner within their physiological "niche" environment while FACS or cryosection could only capture single time-point upon external stimulation to activate satellite cells by BaCl2, Cardiotoxin or ischemia. Furthermore, in vitro transfection with siRNA or overexpression vector could be performed under ex vivo culture to understand the detailed molecular function of a specific gene on SCs physiology. With these advantages, the physiological state of SCs could be analyzed at multiple designated time-points by immunofluorescence staining. In this protocol, we provide an efficient and practical protocol to isolate single myofiber from EDL muscle, followed with ex vivo culture and immunostaining.

Isolation, cultivation and identification of skeletal muscle stem cells derived from human orbicularis oculi muscle / 中华整形外科杂志

Objective@#To establish the isolation and culture methods of skeletal muscle stem cells, derived from human orbicularis oculi muscle (OOMSCs), and to identify their multi-directional differentiation potential in vitro.@*Methods@#The cellswere isolated from pretarsal orbicularis oculi muscle (OOM), obtained in routine blepharoplasty surgery.The tissue was digested using collagenase type I combined with re-plating methods. Specific cell surface antigen markers were detected using flow cytometry analysis. OOMSCs were cultured under different inductive conditions, to identify their pluripotent differentiation ability.@*Results@#OOMSCs exhibited similar fibroblast-like morphology as mesenchymal stem cells with high expression of skeletal muscle-derived stem cell surface markers. OOMSCs were able to differentiate into adipocytes, osteoblasts and chondrocytes in vitro, in the presence of lineage-specific inductive media. Moreover, after myogenic induction, the differentiated cells were fused into multinucleated myotube-like structure, and positive for myogenic-related marks, Pax3, Pax7, Myf5 and MyoD.@*Conclusions@#Muscle-derived stem cells can be isolated from human OOM with myogenic differentiation properties, showing further applications potential intissue regeneration and medical therapies of muscle diseases.

Effect of poly (L-lactic acid caprolactone)/gelatin blend electrospun on angiogenesis of rat bone marrow-derived endothelial progenitor cells / 上海交通大学学报（医学版）

Objective · To investigate the effect of poly (L-lactic acid caprolactone) (PLCL)/gelatin electrospinning on the angiogenesis differentiation of endothelial progenitor cells (EPCs).Methods· Rat bone marrow-derived EPCs were isolated and cultured,then identification was performed.After preparation of PLCL/gelatin blend electrospun scaffold,scanning electron microscopy and water contact angle test were carried out.EPCs were grown on PLCL/gelatin electrospinning and CCK8 was used to detect cell proliferation.The expression of vascular endothelial growth factor (Vegf) and kinases insert region receptor (Kdr) was observed by RT-PCR and the expression of VEGF protein was observed by Western blotting.Results· The density gradient centrifugation combined with differential adherence method could effectively isolate EPCs.PLCL/gelatin electrospun nanofibers were porous,and the hydrophilic properties were favorable for cell adhesion,and EPCs grew well on the scaffold.The expression of Vegfand Kdr gene in PLCL/gelatin group was higher than that in control group (P=0.000),and the expression of VEGF protein was also increased (P=0.000).Conclusion · PLCL/gelatin is an ideal scaffold for tissue engineering,and it can promote the angiogenesis differentiation of EPCs.

Effect of poly (L-lactic acid caprolactone)/gelatin blend electrospun on angiogenesis of rat bone marrow-derived endothelial progenitor cells / 上海交通大学学报（医学版）

Objective: To investigate the effect of poly (L-lactic acid caprolactone) (PLCL) /gelatin electrospinning on the angiogenesis differentiation of endothelial progenitor cells (EPCs). Methods: Rat bone marrow-derived EPCs were isolated and cultured, then identification was performed. After preparation of PLCL/gelatin blend electrospun scaffold, scanning electron microscopy and water contact angle test were carried out. EPCs were grown on PLCL/gelatin electrospinning and CCK8 was used to detect cell proliferation. The expression of vascular endothelial growth factor (Vegf ) and kinases insert region receptor (Kdr) was observed by RT-PCR and the expression of VEGF protein was observed by Western blotting. Results: The density gradient centrifugation combined with differential adherence method could effectively isolate EPCs. PLCL/gelatin electrospun nanofibers were porous, and the hydrophilic properties were favorable for cell adhesion, and EPCs grew well on the scaffold. The expression of Vegf and Kdr gene in PLCL/gelatin group was higher than that in control group (P=0.000), and the expression of VEGF protein was also increased (P=0.000). Conclusion: PLCL/gelatin is an ideal scaffold for tissue engineering, and it can promote the angiogenesis differentiation of EPCs.

Isolation, culture and identification of goat alveolar macrophages / 中国比较医学杂志

Objective In order to study the biological characteristics of macrophages and provide the materials to study the survival mechanism of intracellular parasites, we conducted this study to establish a high-purity alveolar macrophage isolation and culture method.Methods Goat lungs were lavaged with normal saline in sterile environment several times, and cells were collected and then goat alveolar macrophages were purified by density gradient centrifugation using peripheral blood mononuclear cells (PBMC) solution.The isolated goat alveolar macrophages were cultured in cell culture medium containing 10% fetal bovine serum and cell morphology was observed under an inverted microscope every day,and the phagocytic activity of the cells was detected by chicken red blood cell phagocytosis test.Flow cytometry was used to detect CD14, a characteristic monocyte-macrophage surface marker.Results The adherent cells were characterized by typical macrophage morphology, pseudopodia and protrusions, showing round and irregular shape, rich cytoplasm, and large cell body.Of the cultured macrophages, 54.5% could phagocytize chicken erythrocytes and showed good phagocytic activity.After one month of in vitro culture, 93.7% of the cells were able to express CD14 antigen, which had a macrophage-specific immunophenotype.Conclusions The alveolar macrophages obtained in this study have high purity and good bioactivity, thus provide a cell model for studying the immune mechanism of intracellular parasites.

Ex-Vivo Tissues Engineering Modeling for Reconstructive Surgery Using Human Adult Adipose Stem Cells and Polymeric Nanostructured Matrix.

The major challenge for stem cell translation regenerative medicine is the regeneration of damaged tissues by creating biological substitutes capable of recapitulating the missing function in the recipient host. Therefore, the current paradigm of tissue engineering strategies is the combination of a selected stem cell type, based on their capability to differentiate toward committed cell lineages, and a biomaterial, that, due to own characteristics (e.g., chemical, electric, mechanical property, nano-topography, and nanostructured molecular components), could serve as active scaffold to generate a bio-hybrid tissue/organ. Thus, effort has been made on the generation of in vitro tissue engineering modeling. Here, we present an in vitro model where human adipose stem cells isolated from lipoaspirate adipose tissue and breast adipose tissue, cultured on polymeric INTEGRA® Meshed Bilayer Wound Matrix (selected based on conventional clinical applications) are evaluated for their potential application for reconstructive surgery toward bone and adipose tissue. We demonstrated that human adipose stem cells isolated from lipoaspirate and breast tissue have similar stemness properties and are suitable for tissue engineering applications. Finally, the overall results highlighted lipoaspirate adipose tissue as a good source for the generation of adult adipose stem cells.

Stem cell properties and neural differentiation of sheep amniotic epithelial cells.

This study was designed to verify the stem cell properties of sheep amniotic epithelial cells and their capacity for neural differentiation. Immunofluorescence microscopy and reverse transcription-PCR revealed that the sheep amniotic epithelial cells were positive for the embryonic stem cell marker proteins SSEA-1, SSEA-3, SSEA-4, TRA-1-60 and TRA-1-81, and the totipotency-associated genes Oct-4, Sox-2 and Rex-1, but negative for Nanog. Amniotic epithelial cells expressed ß-III-tubulin, glial fibrillary acidic protein, nestin and microtubule-associated protein-2 at 28 days after induction with serum-free neurobasal-A medium containing B-27. Thus, sheep amniotic epithelial cells could differentiate into neurons expressing ß-III-tubulin and microtubule-associated protein-2, and glial-like cells expressing glial fibrillary acidic protein, under specific conditions.

Optimized method for isolating and culturing human nucleus pulposus cells / 中国组织工程研究

BACKGROUND: There are different methods to isolate and culture human nucleus pulposus cells, and the differences in digestive enzymes components and digestion time quite are significant. So how to rapidly and efficiently harvest human nucleus pulposus cells has become a research hotspot. OBJECTIVE: To optimize the digestive enzymes components and digestion methods for the preparation of human nucleus pulposus cells. METHODS: Nucleus pulposus tissue specimens were selected from three adult discs in the Department of Orthopedics, China-Japan Union Hospital of Jilin University. The acute traumatic disc tissues that outstanding to the spinal canal were taken under aseptic conditions, and then the peripheral white annulus and jel y-like nucleus pulposus in the center could be seen. According to different mixed enzyme concentration ratio, the samples were divided into two groups. The enzyme Ⅰ group was treated with 0.2% Ⅱ col agenase; and the mixed enzymeⅡ group was digested with 0.25% trypsin for 30 minutes, and then treated with 0.2% Ⅱ col agenase. According to digestion time, each group was divided into three subgroups: 2 hours group, 4 hours group, and overnight group. Final y, suspended cel volume was decided as 2 mL to count cells. Dulbecco’s modified Eagle’s medium containing fetal bovine serum was used for cel culture in vitro. Trypan blue staining was performed to count total cel number and ratio of living cells. Methylthiazolyldiphenyl-tetrazolium bromide assay was used to detect the growth curve of nucleus pulposus cells. RESULTS AND CONCLUSION: Based on the two digestion enzyme concentration, the number of digested cells in the enzyme Ⅰ group was larger than that in the enzyme Ⅱ group after digested for 2 and 4 hours, but the difference was not significant (P > 0.05). Overnight, cellsurvival rate was decreased in the enzyme Ⅰ group after digested for 2 and 4 hours when compared with the enzyme Ⅱ group, and the difference was significant (P < 0.05). After digested for 4 hours, tissue blocks disappeared, and the number of cells reached maximum. The results indicate that enzyme Ⅰgroup composite with Ⅱ col agenase is benefit for the separation of nucleus pulposus cells, and the digestion time is appropriate to 4 hours. This condition has the advantages of simple operation, high efficiency and low cost, and it considered that digestion of nucleus pulposus tissues with 0.2% Ⅱ col agenase for 4 hours is the best condition to obtain nucleus pulposus cells.

Application of muscle-derived stem cells in tissue engineering and regenerative medicine / 中国组织工程研究

10.3969/j.issn.2095-4344.2013.23.021

STUDIES ON THE TRICHOLOMA GIGANTEUM FROM JISHOU / 微生物学通报

Tricholoma giganteum is a famous species product of Jishou in the wes t of Hunan.It have not only special biological characteristics such as formatio n and ecological enviromment,but also delicious,fragrant with abundant nutrien t.It's mycelium can be isolated and growing well in medium,but its fruiting bo dy is difficult to be formed.