scholarly journals Flow-cytometric analysis of chicken red blood cells.

1978 ◽  
Vol 26 (3) ◽  
pp. 170-186 ◽  
Author(s):  
D Bloch ◽  
N Beaty ◽  
C T Fu ◽  
E Chin ◽  
J Smith ◽  
...  
Keyword(s):  
Sodium Dodecyl ◽  
Flow Cytometric Analysis ◽  
Fluorescence Emission ◽  
Bimodal Distribution ◽  
Parameter Analysis ◽  
Main Peak ◽  
Acceptance Angle ◽  
Flow Cytometric ◽  
High Fluorescence ◽  
Chicken Erythrocytes

Flow-cytometric analysis of acriflavin-Feulgen stained chicken erythrocytes shows a complex distribution of amounts of deoxyribonucleic acid fluorescence, the profile consisting of a main peak and a right hand shoulder. This bimodal distribution, an artifact characteristically seen on analysis of flattened cells using orthogonal flow systems, results from fluorescence emission in preferred directions stemming from the combined effects of refractility and orientation of the cells. The shoulder disappears on analysis of lysed erythrocyte ghosts, also on analysis of cells in a medium whose refractive index approximates that the cells. An orientation effect for matrue erythrocytes was indicated by reanalysis of fractions after sorting on the basis of high and low fluorescence or scatter signals. Both fractions gave the original range of values on reanalysis, although some changes in shape of the profile and in the peak positions for the sorted cells were seen. Sodium dodecyl sulfate treatment of stained cells "loosened" the cells' structure, yielding lowered scatter values, and fluorescence values approaching those of the shoulder. The average fluorescence emission of the erythrocytes was lower than that of reticulocytes and lymphocytes. The values of the latter correspond closely, although coincidently, to that the erythrocyte shoulder values. Dual parameter analysis of forward light scatter, and fluorescence, which was detected at 90 degrees to the laser beam, showed the low fluorescence to be accompanied by low scatter signal, and the high fluorescence among the cells with the high scatter signal. The lowered forward scatter signal is due to a wider scattering of light from cells oriented edge-on to the detector, and loss of signal beyond the acceptance angle of the detector. These results suggest that the preferred directions for fluorescence are in the plane of the cells, and the values are dependent on the cells' orientation in the stream. These interpretations were supported by the results of analysis of partially oriented cells. The approaches used and conclusions arrived at are similar to those of Gledhill et al (16), Van Dilla et al (37), in their analysis of fluorescence of flat sperm cells although the affects in the case of the erythrocytes are less extreme.

Flow cytometric analysis of intracellular pH in 3T3 cells

1987 ◽  
Vol 253 (1) ◽  
pp. C121-C125 ◽  
Author(s):  
R. J. Gillies ◽  
J. Cook ◽  
M. H. Fox ◽  
K. A. Giuliano
Keyword(s):  
Intracellular Ph ◽  
Ph Effect ◽  
Flow Cytometric Analysis ◽  
Fluorescence Emission ◽  
Transformed Cells ◽  
3T3 Cells ◽  
Ph Change ◽  
Cell Responses ◽  
Flow Cytometric ◽  
Serum Components

Techniques to determine intracellular pH generally report the average pH of population and do not indicate whether or not there is significant variance among cells within the population. Population variance is important to ascribe pH changes on a per cell basis. The magnitude of the pH change in individual cells is important to ascribe physiological function to changes in pH. To determine the variability of cell responses, we have used dual wavelength fluorescence emission spectroscopy of intracellular dicyanohydroquinone monitored with flow cytometry to determine the pH of normal and transformed 3T3 cells in response to serum or serum components. All cells were mechanically harvested from subconfluent cultures. Large differences in pH were observed between serum-deprived and serum-conditioned normal, but not transformed, cells. Addition of serum caused cytosolic alkalinization, with the serum-deprived cells responding more slowly. Titration of cells with submaximal doses of serum indicate that the response of pH is graded, that all cells respond in similar manner, and that the relative affinity of transformed cells for the serum components causing the pH effect is about twice that of normal cells.

Calcium homeostasis in dissociated embryonic neurons: a flow cytometric analysis

1992 ◽  
Vol 67 (3) ◽  
pp. 704-714 ◽  
Author(s):  
J. P. Grierson ◽  
R. E. Petroski ◽  
S. M. O'Connell ◽  
H. M. Geller
Keyword(s):  
Calcium Channels ◽  
Calcium Homeostasis ◽  
Flow Cytometric Analysis ◽  
Fluorescence Emission ◽  
Transient Increase ◽  
Metabolic Inhibitors ◽  
Free Calcium ◽  
Free Medium ◽  
Flow Cytometric ◽  
Embryonic Neurons

1. Ca2+ homeostasis in freshly dissociated neurons from embryonic rat hypothalamus, cortex, and brain stem was investigated with flow cytometry. Cells were dissociated from embryonic brain by enzymatic and mechanical means and were incubated with the acetoxymethylester derivative of the Ca(2+)-sensitive dye indo-1. Neurons hydrolyzed and retained the dye as determined by the intensity of fluorescence emission, whereas similarly treated cultured astrocytes gave very low-level fluorescence. 2. The fluorescence of the indo-1 dye was measured at two wavelengths (405 and 485 nm) for each cell. Data were collected only from those cells (presumptive neurons) with high levels of fluorescence. Methods were developed to calibrate the level of intracellular free calcium ([Ca2+]i) as the ratio of fluorescence at 410 and 485 nm. The level of intracellular free Ca2+ was then calculated for each neuron. 3. A wide distribution of resting [Ca2+]i was found, with a median of approximately 90 nM. After addition of ionomycin to cells in Ca(2+)-free medium, there was a transient increase in [Ca2+]i, suggesting that all embryonic neurons had internal Ca2+ stores. The presence of active calcium extrusion mechanisms was demonstrated with the use of ionomycin in Ca(2+)-containing medium and with metabolic inhibitors. Furthermore, incubation in sodium-free medium resulted in a transient increase in [Ca2+]i and a reduced ability to eliminate elevated [Ca2+]i from the cytoplasm, suggesting that calcium homeostasis was dependent on the activity of the Na(+)-Ca2+ exchange mechanism. 4. Depolarization with K+ or veratrine increased [Ca2+]i in approximately 20% of the cells. This increase was blocked by eliminating extracellular free Ca2+ or adding Co2+, nifedipine, or verapamil, suggesting mediation by voltage-sensitive calcium channels. 5. Neurons were sorted on the basis of high [Ca2+]i and placed into dissociated culture. After 24 h, neurons in culture retained indo-1 fluorescence, suggesting that populations of neurons can be collected on the basis of their levels of [Ca2+]i. 6. These results demonstrate that flow cytometric analysis allows the characterization of a variety of Ca(2+)-regulatory mechanisms in populations of freshly dissociated embryonic neurons. Although only a proportion of embryonic day 17 neurons exhibit voltage-sensitive calcium channels, all neurons have developed the ability to sequester and extrude Ca2+.

Quantitative Assessment of Myeloid Nuclear Differentiation Antigen Distinguishes Myelodysplastic Syndrome From Normal Bone Marrow.

Blood ◽  
2009 ◽  
Vol 114 (22) ◽  
pp. 1754-1754
Author(s):  
Head R. Head ◽  
Sara A. McClintock-Treep ◽  
Leanne flye-Blakemore ◽  
Claudio Mosse ◽  
Madan Jagasia ◽  
...  
Keyword(s):  
Flow Cytometric Analysis ◽  
Bimodal Distribution ◽  
Refractory Anemia ◽  
Low Grade ◽  
Differentiation Antigen ◽  
Down Regulation ◽  
Flow Cytometric ◽  
Nuclear Differentiation ◽  
Quantitative Flow ◽  
Myeloid Progenitors

Abstract Abstract 1754 Poster Board I-780 Introduction Definitive diagnosis and classification of MDS are often difficult because of variable presence of diagnostic criteria and imprecision and ambiguities of interpretation of both morphologic and ancillary data. An objective criterion that reliably distinguishes MDS from normal marrow would greatly facilitate diagnosis, and might contribute to subclassification of MDS. Gene expression profiling has identified marked (7 fold) down-regulation of myeloid nuclear differentiation antigen (MNDA) message in cases of MDS (Hofmann WK, et al, Blood 2002;100:3553-60), and we have previously shown down-regulation of MNDA protein expression in random MDS cases using immunohistochemistry and flow cytometry (Briggs RC, et al. Cancer Research 2006;66:4645-51). To continue our previous analyses, we evaluated MNDA expression in myeloid progenitors using quantitative flow cytometric analysis in MDS and normal control marrow samples. Patients and Methods The study included 20 MDS patients receiving only supportive care undergoing bone marrow sampling for clinical purposes, and 19 frequency age-matched normal controls undergoing orthopedic surgery with no antecedent primary hematologic abnormalities. MDS diagnosis was based on 2008 WHO criteria. Quantitative flow cytometric analysis was performed with an FC500 flow cytometer (Beckman Coulter, Fullerton, CA). Cells were treated with CD45-PE and CD34-ECD (Beckman Coulter), washed in PBS with 2% FCS, and permeabilized with PermiFlow. MNDA-Alexa-488 was added at a granulocyte-monocyte specific concentration, with analysis using Winlist 5.0 software (Verity Software, Topsham, ME) with DDE links to ModFitLT 3.0 using modifications of published methods. Differentiating myeloid progenitors were identified as high side scatter/intermediate CD45/CD34-negative cells, with lymphocytes (low side scatter/high CD45/CD34-negative cells) serving as an internal dim MNDA control in each sample. Results MDS cases consisted of 12 patients with refractory cytopenia with multilineage dysplasia (RCMD), 3 with refractory anemia with excess blasts-1(RAEB-1), 4 with RAEB-2, and 1 with therapy-related MDS. In myeloid progenitors in MDS patients, the median percent of MNDA-dim cells was 67.4% (range 0.7-97.5%, interquartile range 44.9-82.7%). The analogous median percent of MNDA-dim cells in control patients was 1.2% (range 0.2-13.7%, interquartile range 0.6-2.7%). The area under the ROC curve was 0.96 (p = 9×10-7), indicating almost complete discrimination between cases and controls. 19 of 20 MDS patients demonstrated bimodal distribution of MNDA expression comprising a distinct MNDA-dim population and a separate MNDA-normal population, suggesting an admixture of MDS and normal cells. 18 of 19 control patients demonstrated a single population of MNDA-normal cells without evidence of a bimodal distribution. The single MDS patient with normal MNDA expression had prior clinical and laboratory features suggestive of refractory anemia with ringed sideroblasts. The single pediatric MDS patient had reduced MNDA expression similar to other high grade MDS samples. Patients showed trends for MDS subtype (p = 0.21) and IPSS score (p = 0.07) versus percent MNDA-dim myeloid progenitors. These data demonstrate remarkable sensitivity and specificity for use of MNDA expression to detect MDS. Conclusions Quantitative flow cytometric analysis of MNDA expression in marrow myeloid progenitors is a promising objective test for diagnosis of MDS, demonstrating a striking difference of MNDA expression in myeloid progenitors in MDS versus control patients. Our results require elaboration with analysis of low grade cases. A single possible low grade MDS case in this series demonstrated MNDA expression identical to normal control samples. Our results also require elaboration in cases constituting the differential diagnosis of MDS to evaluate the clinical utility of MNDA evaluation. The biological significance of down-regulation of MNDA in MDS is uncertain, although MNDA has been implicated in regulation of programmed cell death. Our results suggest a mix of normal and abnormal myelopoiesis in MDS patients, as predicted by cytogenetics in many cases of MDS. In summary, testing of MNDA expression in myeloid progenitors shows great promise as an objective test for diagnosis of MDS in marrow samples. Disclosures No relevant conflicts of interest to declare.

scholarly journals Identification of S-phase cells with PC10 antibody to proliferating cell nuclear antigen (PCNA) by flow cytometric analysis.

1994 ◽  
Vol 42 (8) ◽  
pp. 1177-1182 ◽  
Author(s):  
T Beppu ◽  
Y Ishida ◽  
H Arai ◽  
T Wada ◽  
N Uesugi ◽  
...  
Keyword(s):  
Hela Cells ◽  
Proliferating Cell Nuclear Antigen ◽  
Flow Cytometric Analysis ◽  
Peak Level ◽  
S Phase ◽  
Parameter Analysis ◽  
Nuclear Antigen ◽  
Phase Cell ◽  
Flow Cytometric ◽  
Proliferating Cell

We estimated the expression of proliferating cell nuclear antigen (PCNA) in HeLa S3 cells by flow cytometry with monoclonal antibody (MAb) PC10. HeLa cells were fixed with six different fixation procedures: 15-min and 30-min acetone, 15-min acetone followed by 15-min methanol (acetone/methanol), 30-min methanol, 15-min methanol followed by 15-min acetone (methanol/acetone), and a mixture of acetone and methanol. The fixed cells were applied to MAb PC10 against PCNA and then treated with FITC. With five fixation procedures except for acetone/methanol, PCNA was expressed in almost all cells with similar shapes and different FITC intensity levels on PCNA/DNA bivariate cytograms, whereas acetone/methanol fixation allowed PCNA detection in S-phase cells with a cytogram that showed a horseshoe-like pattern with a peak level at mid-S-phase. Flow cytometric dual parameter analysis of PCNA/BrdU was carried out in HeLa cells to confirm detection of PCNA in S-phase cells with acetone/methanol fixation. The population of cells stained for both parameters, i.e., S-phase cells, was obviously discriminated from that of the non-S-phase cell in PCNA/BrdU bivariate cytograms. These results strongly suggest that PCNA used with acetone/methanol fixation would be equal to BrdU as an S-phase marker.

Study on Europium Polymeric Fluorescent Material and Paper-Based Screen Printing Fluorescent Security Ink

2013 ◽  
Vol 469 ◽  
pp. 7-12
Author(s):  
Jie Meng ◽  
Cheng Sun ◽  
Jian Qing Wang
Keyword(s):  
Screen Printing ◽  
Fluorescence Emission ◽  
Uv Spectra ◽  
Main Peak ◽  
Fluorescence Emission Spectrum ◽  
Fluorescent Material ◽  
Fluorescence Efficiency ◽  
Special Paper ◽  
Fluorescent Agent ◽  
High Fluorescence

Screen printing fluorescent security inks can be widely applied in the field of anti-counterfeiting packaging and printing special. Paper-based screen printing fluorescence security ink was prepared by europium polymer fluorescent material as fluorescent agent, alkyd resin etc as links, meanwhile various additives were added. The performance of europium polymer was studied by IR, UV spectra, fluorescence spectra, and fluorescent security performance of ink were studied by fluorescence spectrophotometer, the results showed that the fluorescence emission spectrum was narrow, and had a main peak at 612nm and high fluorescence efficiency, so this ink had good fluorescence security performance. The fineness,viscosity,stability etc printability of the ink were studied by fineness gauge, viscosity meter, the test result showed that the ink had good printability, can be applied in the security printing process of screen printing.

Apoptotic Effects of Melittin on 4T1 Breast Cancer Cell Line is associated with Up Regulation of Mfn1 and Drp1 mRNA Expression

2020 ◽  
Vol 20 (7) ◽  
pp. 790-799 ◽  
Author(s):  
Farnaz D. Moghaddam ◽  
Pejman Mortazavi ◽  
Somayeh Hamedi ◽  
Mohammad Nabiuni ◽  
Nasim H. Roodbari
Keyword(s):  
Breast Cancer ◽  
Mrna Expression ◽  
Hemolytic Activity ◽  
Breast Cancer Cells ◽  
Flow Cytometric Analysis ◽  
Control Group ◽  
Flow Cytometric ◽  
4T1 Cells ◽  
4T1 Breast Cancer ◽  
Apoptotic Effects

Background and Purpose: Melittin, as the main ingredient of honeybee venom, that has shown anticancer properties. The present study aimed at investigating the cytotoxic impacts of melittin on 4T1 breast cancer cells. Methods: Hemolytic activity of different concentrations (0.125, 0.25, 0.5, 1, 2, 4, 8μg/ml) of melittin was assayed and then cytotoxicity of selected concentrations of melittin (2, 4, 8, 16, 32, and 64μg/ml), 2 and 4μg/ml of cisplatin and 0.513, 0.295 and 0.123μg/ml of doxorubicin was evaluated on 4T1 cells using MTT assay. We used Morphological evaluation and flow cytometric analysis was used. Real time PCR was also used to determine mRNA expression of Mfn1 and Drp1 genes. Results: All compounds showed anti-proliferative effects on the tumor cell line with different potencies. Melittin had higher cytotoxicity against 4T1 breast cancer cells (IC50= 32μg/ml-72h) and higher hemolytic activity (HD50= 1μg/ml), as compared to cisplatin and doxorubicin. Mellitin at 16 and 32μg/ml showed apoptotic effects on 4T1 cells according to the flow cytometric analysis. The Real time PCR analysis of Drp1 and Mfn1 expression in cells treated with 16μg/ml of melittin revealed an up-regulation in Drp1 and Mfn1 genes mRNA expression in comparison with control group. Treatment with 32μg/ml of melittin was also associated with a rise in mRNA expression of Drp1 and Mfn1 as compared to the control group. Conclusion: The results of this study showed that melittin has anticancer effects on 4T1 cell lines in a dose and time dependent manner and can be a good candidate for further research on breast cancer treatment.

scholarly journals Flow cytometric analysis of T lymphocytes and cytokines in aqueous humor of patients with varicella zoster virus-mediated acute retinal necrosis

2021 ◽  
Vol 21 (1) ◽  
Author(s):  
Hao Kang ◽  
Yunbo Wei ◽  
Ming Liu ◽  
Di Yu ◽  
Yong Tao
Keyword(s):  
T Lymphocytes ◽  
Varicella Zoster Virus ◽  
Aqueous Humor ◽  
T Lymphocyte ◽  
Lymphocyte Subsets ◽  
Flow Cytometric Analysis ◽  
T Lymphocyte Subsets ◽  
Varicella Zoster ◽  
Flow Cytometric ◽  
Cd8 T Lymphocytes

Abstract Background The purpose of this study is to investigate the aqueous humor (AH) T lymphocyte subsets and cytokines of acute retinal necrosis (ARN) to elucidate the immunologic inflammatory features of this disorder. Methods Three patients with ARN infected with varicella zoster virus (VZV) who underwent multiple intravitreal injections of ganciclovir were enrolled in this study. The control group consisted of four non-infectious patients with acute anterior uveitis (AAU). Flow cytometric analysis was performed on the lymphocyte subsets from the AH and peripheral blood (PB) samples during the active phase of intraocular inflammation. Five inflammatory cytokines were measured in each AH sample and various clinical characteristics were also assessed. Results VZV deoxyribonucleic acid (DNA) was detected by real-time polymerase chain reaction (PCR) in AH from all the ARN patients, who showed higher CD8+ T lymphocytes population in AH than the AAU patients (p = 0.006). CD4/CD8 ratios of T lymphocytes and the percentage of CD8 + CD25+ T lymphocytes in AH were significantly lower in ARN than in AAU (p = 0.006; p = 0.012). In the ARN patients, the percentages of CD4+ and CD8+ T lymphocytes in AH were higher than those found in PB. The percentage of CD4 + CD25+ T lymphocytes in AH was significantly higher than the proportion in PB in the AAU patients (p = 0.001). Immunoregulatory cytokine Interleukin-10 in AH was significantly elevated in the ARN patients in comparison with the case of the AAU patients (p = 0.036). In ARN, the copy number of VZV DNA in AH positively correlated with the percentage of CD8+ T lymphocytes in AH and negatively correlated with the CD4/CD8 ratio in AH during the course of disease treatment (p = 0.009, r = 0.92; p = 0.039, r = − 0.834). Conclusion The ARN patients caused by VZV had different intraocular T lymphocyte subsets and cytokines profile than those of the non-infectious patients. High percentages of CD8+ T lymphocytes and low CD4/CD8 T cell ratios may be a potential biomarker for diagnosis of viral-infectious uveitis. T lymphocytes examination at the inflammatory sites has the potential to become a useful research tool for differentiating viral and non-viral uveitis.

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