scholarly journals Quantification of non-specific binding of magnetic micro- and nanoparticles using cell tracking velocimetry: Implication for magnetic cell separation and detection

2010 ◽  
pp. n/a-n/a ◽  
Author(s):  
J.J. Chalmers ◽  
Y. Xiong ◽  
X. Jin ◽  
M. Shao ◽  
X. Tong ◽  
...  
Keyword(s):  
Cell Separation ◽  
Cell Tracking ◽  
Specific Binding ◽  
Magnetic Cell Separation ◽  
Cell Tracking Velocimetry

Potential of Cell Tracking Velocimetry as an Economical and Portable Hematology Analyzer

2021 ◽  
Author(s):  
Jenifer Gómez-Pastora ◽  
James Kim ◽  
Mitchell Weigand ◽  
Andre F. Palmer ◽  
Mark Yazer ◽  
...  
Keyword(s):  
Cell Volume ◽  
Cell Tracking ◽  
Point Of Care ◽  
Reference Ranges ◽  
Red Cell ◽  
Normal Range ◽  
Red Cell Volume ◽  
Short Period ◽  
Hematology Analyzer ◽  
Cell Tracking Velocimetry

Abstract Anemia and iron deficiency continue to be the most prevalent nutritional disorders in the world, affecting billions of people in both developed and developing countries. The initial diagnosis of anemia is typically based on several markers, including red blood cell (RBC) count, hematocrit and total hemoglobin. Using modern hematology analyzers, erythrocyte parameters such as mean corpuscular volume (MCV), mean corpuscular hemoglobin (MCH), etc. are also being used. However, most of these commercially available analyzers pose several disadvantages: they are expensive instruments that require significant bench space and are heavy enough to limit their use to a specific lab and leading to a delay in results, making them less practical as a point-of-care instrument that can be used for swift clinical evaluation. Thus, there is a need for a portable and economical hematology analyzer that can be used at the point of need. In this work, we evaluated the performance of a system referred to as the cell tracking velocimetry (CTV) to measure several hematological parameters from fresh human blood obtained from healthy donors. Our system, based on the paramagnetic behavior that methemoglobin containing RBCs experience when suspended in water after applying a magnetic field, uses a combination of magnets and microfluidics and has the ability to track the movement of thousands of red cells in a short period of time. This allows us to measure not only traditional RBC indices but also novel parameters that are only available for analyzers that assess erythrocytes on a cell by cell basis. As such, we report, for the first time, the use of our CTV as a hematology analyzer that is able to measure red cell volume or MCV, red cell hemoglobin mass or MCH, hemoglobin concentration (MCHC), red cell distribution width (RDW) and the percentage of hypochromic cells, which is an indicator of insufficient marrow iron supply that reflects recent iron reduction. Our initial results indicate that most of the parameters measured with CTV are within the normal range for healthy adults. Only the parameters related to the red cell volume (primarily MCV and RDW) were outside the normal range. We observed significant discrepancies between the MCV measured by our technology (and also by an automated cell counter) and the manual MCV measured through the hematocrit obtained by packed cell volume method, which are attributed to the artifacts of plasma trapping and cell shrinkage. While there may be limitations for measuring MCV, this device offers a novel point of care instrument to provide rapid RBC parameters such as iron stores that are otherwise not rapidly available to the clinician. Thus, our CTV is a promising technology with the potential to be employed as an accurate, economical, portable and fast hematology analyzer after applying instrument-specific reference ranges or correction factors.

scholarly journals Isolating astrocytes and neurons sequentially from postnatal murine brains with a magnetic cell separation technique

2014 ◽  
Vol 1 (2) ◽  
pp. 11 ◽  
Author(s):  
Maria Feldmann ◽  
Praneeti Pathipati ◽  
R Ann Sheldon ◽  
Xiangning Jiang ◽  
Donna M Ferriero
Keyword(s):  
Cell Separation ◽  
Separation Technique ◽  
Magnetic Cell Separation

scholarly journals Intrinsically magnetic susceptibility in human blood and its impact on cell separation: Non-classical and intermediate monocytes have the strongest magnetic behavior in fresh human blood

2021 ◽  
Author(s):  
Jenifer Gómez-Pastora ◽  
James Kim ◽  
Victor Multanen ◽  
Mitchell Weigand ◽  
Nicole Walters ◽  
...  
Keyword(s):  
Magnetic Properties ◽  
Red Blood Cells ◽  
Human Blood ◽  
Blood Cells ◽  
Cell Tracking ◽  
Magnetic Behavior ◽  
Immunomagnetic Separation ◽  
Iron Storage ◽  
Cell Tracking Velocimetry ◽  
Classical Monocytes

The presence of iron in circulating monocytes is well known as they play an essential role in iron recycling. It has been demonstrated that the iron content of blood cells can be measured through their magnetic behavior; however, the magnetic properties of different monocyte subtypes remain unknown. In this study, we report for the first time, the magnetic behavior of classical, intermediate and non-classical monocytes, which is related to their iron storage capacity. The magnetic properties of monocytes were compared to other blood cells, such as lymphocytes and red blood cells in the oxyhemoglobin and methemoglobin states, and a cancer cell type. For this analysis, we used an instrument referred to as Cell Tracking Velocimetry (CTV), which quantitatively characterizes the magnetic behavior of biological entities. Our results demonstrate that significant fractions of the intermediate and non-classical monocytes have high magnetophoretic mobilities, equivalent to methemoglobin red blood cells and higher than the classical subset, suggesting their higher iron storage capacities. Moreover, our findings have implications for the immunomagnetic separation industry; we demonstrate that negative magnetic isolation techniques for recovering monocytes from blood should be used with caution, as it is possible to lose magnetic monocytes when using this technique.

Theoretical and experimental analysis of the accuracy and reproducibility of cell tracking velocimetry

2001 ◽  
Vol 30 (4) ◽  
pp. 371-380 ◽  
Author(s):  
M. Nakamura ◽  
M. Zborowski ◽  
L. C. Lasky ◽  
S. Margel ◽  
J. J. Chalmers
Keyword(s):  
Experimental Analysis ◽  
Cell Tracking ◽  
Cell Tracking Velocimetry

Clinical Scale Enrichment and Expansion of Highly Pure CD25+Foxp3+ Regulatory T Cells.

Blood ◽  
2010 ◽  
Vol 116 (21) ◽  
pp. 3718-3718
Author(s):  
Carina Conrads ◽  
Jürgen Schmitz ◽  
Mario Assenmacher ◽  
Claudia Niemand ◽  
Alexander Scheffold
Keyword(s):  
Clinical Application ◽  
Cell Separation ◽  
Foxp3 Expression ◽  
Clinical Scale ◽  
Organ Rejection ◽  
Immune Mediated ◽  
In Vitro Expansion ◽  
Magnetic Cell Separation ◽  
Effector Cytokines

Abstract Abstract 3718 CD25+Foxp3+ regulatory T cell (Treg) bear great potential to prevent or treat a variety of immune mediated diseases, including autoimmunity, organ rejection or GvHD. Currently Treg for clinical application can be separated by magnetic cell separation via the CliniMACS® Plus Instrument using CD25 enrichment plus/minus prior depletion of CD8 or CD19 positive cells. With this technology Treg can be enriched to a mean purity of about 50% and first clinical trials for prevention of GvHD show no adverse effects at all. Despite these promising results, concerns have been raised whether in the setting of organ transplantation or autoimmunity higher Treg purities and/or the in vitro expansion of Treg without loss of Foxp3+ expression are required. Therefore, we have optimized the parameters for CD25 enrichment via CliniMACS to achieve higher purity of the isolated Treg. The purity of Treg could be increased by about 20–30% resulting in an average purity of 70–80% of Foxp3+ Treg. We have also developed a protocol for the in vitro expansion of CliniMACS isolated Treg using CD3/CD28 coated MACSiBead™Particles. In the presence of Rapamycin CliniMACS isolated Treg could be expanded about 20 fold with a single round of stimulation. Importantly Foxp3+ expression was not affected by the expansion but remained constant at about 70–80%. Similarly the expression of effector cytokines by expanded Treg was greatly suppressed by Rapamycin. These data show that Treg for clinical application can efficiently be isolated with high purity via CliniMACS and subsequently be expanded in vitro without loss of Foxp3 expression. Disclosures: Conrads: Miltenyi Biotec: Employment. Schmitz:Miltenyi Biotec: Employment. Assenmacher:m: Employment. Niemand:Miltenyi Biotec: Employment. Scheffold:Miltenyi Biotec: Employment.

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