Rapid method for the isolation of neutrophils in high yield without the use of dextran or density gradient polymers

1989 ◽  
Vol 121 (1) ◽  
pp. 105-113 ◽  
Author(s):  
Paul Eggleton ◽  
Robert Gargan ◽  
Derek Fisher
Keyword(s):  
Density Gradient ◽  
Rapid Method ◽  
High Yield ◽  
Gradient Polymers

scholarly journals Comparison of Tissue Loading Before and After the Creation of a Continuous Density Gradient in Porcine Islet Purification

Cell Medicine ◽  
2018 ◽  
Vol 10 ◽  
pp. 215517901878134 ◽  
Author(s):  
Chika Miyagi-Shiohira ◽  
Yoshiki Nakashima ◽  
Nana Ebi ◽  
Eri Hamada ◽  
Yoshihito Tamaki ◽  
...  
Keyword(s):  
Density Gradient ◽  
Stimulation Index ◽  
High Yield ◽  
Pancreatic Islet Transplantation ◽  
Post Transplantation ◽  
Porcine Pancreas ◽  
Purification Method ◽  
Continuous Density ◽  
Porcine Islet ◽  
The Impact

The purification step is one of the most important and difficult procedures in islet isolation for pancreatic islet transplantation. We previously reported that a purification method using large plastic bottles effectively achieved a high yield of islets from the porcine pancreas. In this study, we evaluated the impact of the timing of tissue loading on porcine islet purification using large plastic bottles. One method involved loading digested tissue after creating a continuous density gradient (tissue after gradient [TAG]). The other method involved loading digested tissue before creating a continuous density gradient (tissue before gradient [TBG]). There were no significant differences between TAG and TBG in terms of the islet yield, rates of viability and purity, score, and in the stimulation index after purification. Furthermore, there were no marked differences in the attainability or suitability of post-transplantation normoglycemia. Our study shows the equivalency of these two methods of islet purification.

Dielectrophoretic technique for the preparation of density gradient polymers doped with a dipolar modifier

2003 ◽  
Vol 11 (6) ◽  
pp. 467-470 ◽  
Author(s):  
Dong-Jin Woo ◽  
Jeong Min Mun ◽  
Suck-Hyun Lee ◽  
Moon Ho Suh
Keyword(s):  
Density Gradient ◽  
Gradient Polymers

scholarly journals The Evaluation of Islet Purification Methods That Use Large Bottles to Create a Continuous Density Gradient

Cell Medicine ◽  
2017 ◽  
Vol 9 (1-2) ◽  
pp. 45-51 ◽  
Author(s):  
Chika Miyagi-Shiohira ◽  
Naoya Kobayashi ◽  
Issei Saitoh ◽  
Masami Watanabe ◽  
Yasufumi Noguchi ◽  
...  
Keyword(s):  
Stainless Steel ◽  
Density Gradient ◽  
Stimulation Index ◽  
High Density ◽  
Steel Pipe ◽  
High Yield ◽  
Low Density ◽  
Pancreatic Islet Transplantation ◽  
Continuous Density ◽  
Stainless Steel Pipe

Islet purification is one of the most important steps of islet isolation for pancreatic islet transplantation. The most common method of islet purification is density gradient centrifugation using a COBE 2991 cell processor. However, this method can damage islets mechanically through its high shearing force. We recently reported that a new purification method using large plastic bottles effectively achieves a high yield of islets from the porcine pancreas. In the present study, we evaluated the methods of making a continuous density gradient. The gradient was produced with a gradient maker and two types of candy cane-shaped stainless steel pipes. One method was to use a “bent-tipped” stainless steel pipe and to load from a high-density solution to a low-density solution, uploading the stainless steel pipe. The other method was to use a regular stainless steel pipe and to load from a low-density solution to a high-density solution, leaving the stainless steel pipe in place. There were no significant differences between the two solutions in terms of the islet yield, rate of viability or purity, score, or the stimulation index after purification. Furthermore, there were no differences in the attainability or suitability of posttransplantation normoglycemia. Our study shows the equivalency of these two methods of islet purification.

A rapid method of constructing density gradient tubes

1955 ◽  
Vol 17 (85) ◽  
pp. 441-442 ◽  
Author(s):  
L. H. Tung ◽  
W. C. Taylor
Keyword(s):  
Density Gradient ◽  
Rapid Method

Microgravity Separation of Alginate Empty Capsules from Encapsulated Pancreatic Islets Using a Microfluidic System

2015 ◽  
Vol 15 (10) ◽  
pp. 7876-7880 ◽  
Author(s):  
Soojeong Shin ◽  
Young Je Yoo ◽  
Jong Wook Hong
Keyword(s):  
Pancreatic Islets ◽  
Density Gradient ◽  
Density Gradient Centrifugation ◽  
Biomedical Application ◽  
Gradient Centrifugation ◽  
Previous Method ◽  
High Yield ◽  
One Pot ◽  
Optimal Separation

Although microencapsulated pancreatic islets have merits, such as ease of transplantation, viability and functionality improvement, and immune protection in vivo, the co-production of alginate empty capsules during the encapsulation of islets with alginate makes them unusable for biomedical application. In previous research, the removal of empty alginate capsules with high yield was achieved using density-gradient centrifugation. Here, we report advanced microgravity-based separation techniques in a microfluidic format for alginate empty capsules. The optimal separation conditions were mathematically evaluated using Stokes’ law and the separation of the encapsulation product was accomplished. A microfluidic chip was designed with two inlets and two outlets at different elevations to mimic the vertical percoll gradient in density-gradient centrifugation. The separation of alginate empty capsules using microgravitational force resulted in effective separation of encapsulated islets from alginate empty capsules with more than 70% efficiency. Moreover, no loss of encapsulated islets was expected because the process is a one-pot separation, unlike the previous method. This type of microgravitational particle separation could be used both for the fractionization of heterogeneous encapsulated cells and to remove empty capsules.

Rapid assay of poly(ADP-ribose) glycohydrolase

1987 ◽  
Vol 65 (7) ◽  
pp. 668-673 ◽  
Author(s):  
Luc Ménard ◽  
Guy G. Poirier
Keyword(s):  
Thin Layer ◽  
Enzymatic Activity ◽  
Affinity Chromatography ◽  
Thin Layer Chromatography ◽  
Rapid Method ◽  
The Other ◽  
High Yield ◽  
Rapid Assay ◽  
Layer Chromatography

We have developed a rapid, highly reproducible assay to determine poly(ADP-ribose) glycohydrolase activity which measures directly the appearance of the reaction product. We also analysed the majority of different techniques which are used to determine poly(ADP-ribose) glycohydrolase activity and found that the apparent activity can vary extensively depending on the method used. Thin-layer chromatography using PEI-F–cellulose was the only method which evaluated directly the specific release of ADP-ribose; by comparison with this method, the other procedures gave an over- or under-estimation of 2- to 10-fold of the enzymatic activity. A rapid method of affinity chromatography has also been developed to synthesize and purify in high yield poly(ADP-ribose) (35% conversion of 1 mM NAD to poly (ADP-ribose)).

A high yield of fetal nucleated red blood cells isolated using optimal osmolality and a double-density gradient system

2007 ◽  
Vol 27 (13) ◽  
pp. 1245-1250 ◽  
Author(s):  
K. H. Kwon ◽  
Y. J. Jeon ◽  
H. S. Hwang ◽  
K. A. Lee ◽  
Y. J. Kim ◽  
...  
Keyword(s):  
Red Blood Cells ◽  
Density Gradient ◽  
Blood Cells ◽  
High Yield ◽  
Gradient System ◽  
Nucleated Red Blood Cells

An improved procedure for the purification of apple chlorotic leaf spot virus

1992 ◽  
Vol 72 (3) ◽  
pp. 937-941
Author(s):  
Delano James ◽  
Paul L. Monette
Keyword(s):  
Density Gradient ◽  
Leaf Spot ◽  
Gradient Centrifugation ◽  
Chenopodium Quinoa ◽  
Sucrose Density Gradient ◽  
High Yield ◽  
Spot Virus ◽  
Virus Particles ◽  
Intact Virus ◽  
Chlorotic Leaf

A reproducible procedure is described for the purification of apple chlorotic leaf spot virus (CLSV) from Chenopodium quinoa. Two cycles of sucrose density-gradient centrifugation in a magnesium-containing buffer were used. A relatively high yield of virus particles was obtained with little degradation observed. The average yield was 2.3 mg 100 g−1 fresh leaf tissue. The modal lengths of purified virus particles and particles from leaf sap were 692 nm and 704 nm, respectively.Key words: Chenopodium quinoa, sucrose density gradient, magnesium-containing buffer, intact virus

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