scholarly journals Robust Estimation of Bacterial Cell Count from Optical Density

2019 ◽  
Author(s):  
Jacob Beal ◽  
Natalie G. Farny ◽  
Traci Haddock-Angelli ◽  
Vinoo Selvarajah ◽  
Geoff S. Baldwin ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Count ◽  
Optical Density ◽  
Low Cost ◽  
Serial Dilution ◽  
Interlaboratory Study ◽  
Silica Microspheres ◽  
Flow Cytometry Data ◽  
E Coli ◽  
Calibration Protocol

AbstractOptical density (OD) is a fast, cheap, and high-throughput measurement widely used to estimate the density of cells in liquid culture. These measurements, however, cannot be compared between instruments without a standardized calibration protocol and are challenging to relate to actual cell count. We address these shortcomings with an interlaboratory study comparing three OD calibration protocols, as applied to eight strains of E. coli engineered to constitutively express varying levels of GFP. These three protocols—comparison with colloidal silica (LUDOX), serial dilution of silica microspheres, and a reference colony-forming unit (CFU) assay—are all simple, low-cost, and highly accessible. Based on the results produced by the 244 teams completing this interlaboratory study, we recommend calibrating OD using serial dilution of silica microspheres, which readily produces highly precise calibration (95.5% of teams having residuals less than 1.2-fold), is easily assessed for quality control, and as a side effect also assesses the effective linear range of an instrument. Moreover, estimates of cell count from silica microspheres can be combined with fluorescence calibration against fluorescein to obtain units of Molecules of Equivalent Fluorescein (MEFL), allowing direct comparison and data fusion with equivalently calibrated flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.

scholarly journals Robust estimation of bacterial cell count from optical density

2020 ◽  
Vol 3 (1) ◽  
Author(s):  
Jacob Beal ◽  
◽  
Natalie G. Farny ◽  
Traci Haddock-Angelli ◽  
Vinoo Selvarajah ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Cell Count ◽  
Optical Density ◽  
Liquid Culture ◽  
Low Cost ◽  
Silica Microspheres ◽  
Flow Cytometry Data ◽  
E Coli ◽  
Plate Reader ◽  
Calibration Protocol

AbstractOptical density (OD) is widely used to estimate the density of cells in liquid culture, but cannot be compared between instruments without a standardized calibration protocol and is challenging to relate to actual cell count. We address this with an interlaboratory study comparing three simple, low-cost, and highly accessible OD calibration protocols across 244 laboratories, applied to eight strains of constitutive GFP-expressing E. coli. Based on our results, we recommend calibrating OD to estimated cell count using serial dilution of silica microspheres, which produces highly precise calibration (95.5% of residuals  <1.2-fold), is easily assessed for quality control, also assesses instrument effective linear range, and can be combined with fluorescence calibration to obtain units of Molecules of Equivalent Fluorescein (MEFL) per cell, allowing direct comparison and data fusion with flow cytometry measurements: in our study, fluorescence per cell measurements showed only a 1.07-fold mean difference between plate reader and flow cytometry data.

scholarly journals THE EFFECTS OF SULFATHIAZOLE AND OF PROPYL CARBAMATE ON THE RATE OF OXYGEN CONSUMPTION AND GROWTH IN ESCHERICHIA COLI

1947 ◽  
Vol 30 (3) ◽  
pp. 263-278 ◽  
Author(s):  
Kenneth C. Fisher ◽  
Florence H. Armstrong
Keyword(s):  
Escherichia Coli ◽  
Oxygen Consumption ◽  
Cell Count ◽  
Optical Density ◽  
Viable Cell ◽  
E Coli ◽  
Rate Of Growth ◽  
A Value ◽  
Rate Of Oxygen Consumption ◽  
Rates Of Growth

1. The rates of growth and of oxygen consumption by cells of E. coli have been measured under identical conditions, and the effects of sulfathiazole (ST) and of n-propyl carbamate (PC) on these two processes have been compared. 2. The rate of growth was measured by (a) the increase in the viable cell count, (b) the increase in the optical density of the culture, (c) the increase in the rate of oxygen consumption, and (d) the decrease in the ammonia of the medium. The results as indicated by these several measures were identical under the conditions of these experiments. 3. Concentrations of ST or of PC which are just sufficient to stop growth completely, lower the rate of oxygen consumption per unit of bacterial protoplasm to a value approximately 50 per cent of that seen in the absence of the inhibitor. 4. It is shown that the rate of oxygen consumption in cells from old cultures is less affected by ST than is the rate of oxygen consumption by cells from young cultures. It is probable that the rate of oxygen consumption by "old" cells is lower than that of "young" cells. 5. The effects of ST and PC on both the rate of oxygen consumption and the rate of growth are very similar, indicating in a general way, that the mechanism of the actions of these two inhibitors is similar. Furthermore, since both of them produce appreciable inhibition of the rate of oxygen consumption while they are inhibiting growth, the possibility that the effect on oxygen consumption is the immediate cause of the effect on growth must be entertained.

scholarly journals Peripheral Blood Examination Findings in SARS-CoV-2 Infection

2020 ◽  
Vol 154 (3) ◽  
pp. 319-329 ◽  
Author(s):  
Alia Nazarullah ◽  
Christine Liang ◽  
Andrew Villarreal ◽  
Russell A Higgins ◽  
Daniel D Mais
Keyword(s):  
Flow Cytometry ◽  
T Cell ◽  
Cell Count ◽  
Peripheral Blood ◽  
Flow Cytometric Analysis ◽  
Control Group ◽  
Flow Cytometry Data ◽  
Blood Smears ◽  
Complete Blood Counts ◽  
Peripheral Blood Smears

Abstract Objectives Peripheral blood abnormalities in severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) have not been fully elucidated. We report qualitative and quantitative peripheral blood findings in coronavirus disease 2019 (COVID-19) patients and compare them with a control group. Methods We reviewed electronic medical records, complete blood counts, peripheral blood smears, and flow cytometry data in 12 patients with SARS-CoV-2. These were compared with 10 control patients with symptoms suspicious for SARS-CoV-2 but who tested negative. Results No significant differences were noted in blood counts, except that absolute lymphopenia was present frequently in the control group (P &lt; .05). Acquired Pelger-Huët anomaly (APHA) was noted in all COVID-19 cases, in most cases affecting over 5% of granulocytes. This contrasted with APHA in only 50% of control cases, affecting fewer than 5% of granulocytes in all cases (P &lt; .05). Monolobate neutrophils were exclusive to COVID-19 cases. COVID-19 patients had greater frequency of plasmacytoid lymphocytes (P &lt; .05). Flow cytometry data revealed absolute CD3+ T-cell count reduction in 6 of 7 patients; all of them required mechanical ventilation. Conclusions Lymphopenia was infrequent in our COVID-19 cohort; however, flow cytometric analysis revealed absolute T-cell count reduction in most cases. COVID-19 cases had significant APHA with monolobate neutrophils and plasmacytoid lymphocytes as compared to controls.

scholarly journals Recent Bioinformatics Advances in the Analysis of High Throughput Flow Cytometry Data

2009 ◽  
Vol 2009 ◽  
pp. 1-2
Author(s):  
Raphael Gottardo ◽  
Ryan R. Brinkman ◽  
George Luta ◽  
Matt P. Wand
Keyword(s):  
Flow Cytometry ◽  
High Throughput ◽  
Flow Cytometry Data

scholarly journals Automated gating of flow cytometry data via robust model-based clustering

2008 ◽  
Vol 73A (4) ◽  
pp. 321-332 ◽  
Author(s):  
Kenneth Lo ◽  
Ryan Remy Brinkman ◽  
Raphael Gottardo
Keyword(s):  
Flow Cytometry ◽  
Model Based Clustering ◽  
Flow Cytometry Data ◽  
Model Based ◽  
Robust Model

Multicenter Comparison of CD34+ Myeloid Cell Count by Flow Cytometry in Low-Risk Myelodysplastic Syndrome. Is It Feasible?

2017 ◽  
Vol 55 ◽  
pp. S98-S99
Author(s):  
P. Font ◽  
D. Subira ◽  
S. Matarraz ◽  
C. Benavente ◽  
T. Cedena ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Myelodysplastic Syndrome ◽  
Cell Count ◽  
Myeloid Cell ◽  
Low Risk

scholarly journals Lipopolysaccharides of Fusobacterium nucleatum and Porphyromonas gingivalis increase RANKL-expressing neutrophils in air pouches of mice

2021 ◽  
Vol 37 (1) ◽  
Author(s):  
Ae Ri Kim ◽  
Yun Kyong Lim ◽  
Joong-Ki Kook ◽  
Eun-Jung Bak ◽  
Yun-Jung Yoo
Keyword(s):  
Flow Cytometry ◽  
Porphyromonas Gingivalis ◽  
Osteoclast Differentiation ◽  
Fusobacterium Nucleatum ◽  
Pathological Changes ◽  
Air Pouch ◽  
E Coli ◽  
Differentiation Factor ◽  
Osteoclast Differentiation Factor

AbstractIncreases of neutrophils and osteoclasts are pathological changes of periodontitis. RANKL is an osteoclast differentiation factor. The effect of periodontopathogen LPS on RANKL-expressing neutrophils has not been clarified yet. We evaluated numerical changes of RANKL-expressing neutrophils in air pouches of mice injected with LPSs of Fusobacterium nucleatum and Porphyromonas gingivalis. Mice with air pouches were assigned into saline (C)-, E. coli LPS- (Ec LPS)-, F. nucleatum LPS (Fn LPS)-, P. gingivalis LPS (Pg LPS)-, and Fn LPS and Pg LPS (Fn + Pg LPS)-injected groups. CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils in blood and air pouch exudates were determined by flow cytometry. In blood, compared to the C group, the Fn LPS group showed increases of CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils whereas the Pg LPS group showed no significant differences. These increases in the Fn LPS group were not different to those in the Ec LPS group. In exudates, Fn LPS and Pg LPS groups showed increases of CD11b+Ly6G+ neutrophils and CD11b+Ly6G+RANKL+ neutrophils compared to the C group. Increased levels in the Fn LPS group were not different to those in the Ec LPS group, but Pg LPS group was lower than those in the Ec LPS group. In blood and exudates, the Fn + Pg LPS group showed no difference in levels of these neutrophils compared to the Ec LPS group. LPSs of F. nucleatum and P. gingivalis increased RANKL-expressing neutrophils although the degrees of increases were different. These suggest that periodontopathogen LPS can act as a stimulant to increase RANKL-expressing neutrophils.

Natural polyploidy in Vanilla planifolia (Orchidaceae)

Genome ◽  
2008 ◽  
Vol 51 (10) ◽  
pp. 816-826 ◽  
Author(s):  
Séverine Bory ◽  
Olivier Catrice ◽  
Spencer Brown ◽  
Ilia J. Leitch ◽  
Rodolphe Gigant ◽  
...  
Keyword(s):  
Flow Cytometry ◽  
Phenotypic Variation ◽  
Chromosome Numbers ◽  
Reunion Island ◽  
Vanilla Planifolia ◽  
Root Cells ◽  
Flow Cytometry Data ◽  
Important Variation ◽  
Réunion Island ◽  
Stomatal Length

Vanilla planifolia accessions cultivated in Reunion Island display important phenotypic variation, but little genetic diversity is demonstrated by AFLP and SSR markers. This study, based on analyses of flow cytometry data, Feulgen microdensitometry data, chromosome counts, and stomatal length measurements, was performed to determine whether polyploidy could be responsible for some of the intraspecific phenotypic variation observed. Vanilla planifolia exhibited an important variation in somatic chromosome number in root cells, as well as endoreplication as revealed by flow cytometry. Nevertheless, the 2C-values of the 50 accessions studied segregated into three distinct groups averaging 5.03 pg (for most accessions), 7.67 pg (for the ‘Stérile’ phenotypes), and 10.00 pg (for the ‘Grosse Vanille’ phenotypes). For the three groups, chromosome numbers varied from 16 to 32, 16 to 38, and 22 to 54 chromosomes per cell, respectively. The stomatal length showed a significant variation from 37.75 µm to 48.25 µm. Given that 2C-values, mean chromosome numbers, and stomatal lengths were positively correlated and that ‘Stérile’ and ‘Grosse Vanille’ accessions were indistinguishable from ‘Classique’ accessions using molecular markers, the occurrence of recent autotriploid and autotetraploid types in Reunion Island is supported. This is the first report showing evidence of a recent autopolyploidy in V. planifolia contributing to the phenotypic variation observed in this species.

scholarly journals Normative data for flow cytometry immunophenotyping of benign lymph nodes sampled by surgical biopsy

2017 ◽  
Vol 71 (2) ◽  
pp. 174-179 ◽  
Author(s):  
Gregory David Scott ◽  
Susan K Atwater ◽  
Dita A Gratzinger
Keyword(s):  
Flow Cytometry ◽  
Lymph Node ◽  
T Cell ◽  
Lymph Nodes ◽  
Inflammatory Disease ◽  
Clinical History ◽  
Surgical Biopsy ◽  
Data Set ◽  
Flow Cytometry Data ◽  
Benign Lymph Node

AimsTo create clinically relevant normative flow cytometry data for understudied benign lymph nodes and characterise outliers.MethodsClinical, histological and flow cytometry data were collected and distributions summarised for 380 benign lymph node excisional biopsies. Outliers for kappa:lambda light chain ratio, CD10:CD19 coexpression, CD5:CD19 coexpression, CD4:CD8 ratios and CD7 loss were summarised for histological pattern, concomitant diseases and follow-up course.ResultsWe generated the largest data set of benign lymph node immunophenotypes by an order of magnitude. B and T cell antigen outliers often had background immunosuppression or inflammatory disease but did not subsequently develop lymphoma.ConclusionsDiagnostic immunophenotyping data from benign lymph nodes provide normative ranges for clinical use. Outliers raising suspicion for B or T cell lymphoma are not infrequent (26% of benign lymph nodes). Caution is indicated when interpreting outliers in the absence of excisional biopsy or clinical history, particularly in patients with concomitant immunosuppression or inflammatory disease.

Sign in / Sign up

Export Citation Format

Share Document