Free Flow Isoelectric Focusing in a Microfluidic Device

2014 ◽  
Author(s):  
Kisoo Yoo ◽  
Prashanta Dutta ◽  
Jin Liu
Keyword(s):  
Mathematical Model ◽  
Isoelectric Focusing ◽  
Microfluidic Device ◽  
Microfluidic Chip ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Free Flow ◽  
Charged Species ◽  
Simulation Results ◽  
Separation Of Proteins

In recent years, there are growing interests in the use of free flow isoelectric focusing (FFIEF). In FFIEF, a thin sheath of laminar flow is introduced perpendicular to the direction of the applied electric field for continuous separation of proteins and charged species. This technique is especially useful in microfluidic device since the electrophoretically separated bands do not have to be mobilized for detection or further analysis. In this study, a mathematical model is developed to simulate free flow isoelectric process in microfluidic devices considering electroneutrality and incompressibility of electrolytes. Our mathematical model is based on mass, momentum and charge conservation equations. A finite volume based numerical scheme is implemented to simulate two dimensional FFIEF in a microfluidic chip. Simulation results indicate that pH gradient forms as samples flow downstream and proteins can be separated effectively using this technique. A new design of microfluidic chip is proposed for separation for cardiac troponin I from serum albumin using FFIEF technique.

Cardiac Troponin I Microfluidic Chip Driven by Adaptive Pressure

2020 ◽  
Vol 12 (10) ◽  
pp. 1239-1247
Author(s):  
Xingshang Xu ◽  
Yuan Liu ◽  
Zhu Chen ◽  
Hui Chen ◽  
Yan Deng ◽  
...  
Keyword(s):  
Microfluidic Chip ◽  
Whole Blood ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Accurate Determination ◽  
Cardiac Troponin I ◽  
Chip Surface ◽  
Layer Composite ◽  
Novel Strategy ◽  
The Stability

To develop and design an adaptive microfluidic chip for accurate determination of cardiac troponin I (cTnI) in whole blood sample and explore the operating parameters of the chip in detecting cTnI, in order to provide a novel strategy for the detection of cTnI, cTnI microfluidic chip was prepared by injection moulding, and the improved polystyrene polymer was used as the chip substrate to construct a three-layer composite structure, namely the upper, middle, and lower layers. The antihuman troponin I antibody I/II was grafted onto the chip surface to construct the detection reaction zone using UV-induced production of surface-active free radicals. The stability of the chip preparation process, the running performance of the chip, and the analytical performance of the whole blood samples were investigated. It was shown that I adaptive pressure-driven microfluidic chip has the advantages of easy bonding, integration, and a simple and stable production process. In the actual detection and analysis, the chip has high selectivity for cTnI in whole blood, lower detection limit (0.054 ng/mL), and small difference between batches (RSD% 2.50%). Therefore, the chip is assumed to provide novel strategy for the assessment of myocardial infarction by detecting cTnI.

Sub-second isoelectric focusing in free flow using a microfluidic device

Lab on a Chip ◽  
2003 ◽  
Vol 3 (4) ◽  
pp. 224 ◽  
Author(s):  
Yi Xu ◽  
Chao-Xuan Zhang ◽  
Dirk Janasek ◽  
Andreas Manz
Keyword(s):  
Isoelectric Focusing ◽  
Microfluidic Device ◽  
Free Flow

Reciprocating free-flow isoelectric focusing device for preparative separation of proteins

2015 ◽  
Vol 1422 ◽  
pp. 318-324 ◽  
Author(s):  
Fan-Zhi Kong ◽  
Ying Yang ◽  
Yi Wang ◽  
Guo-Qing Li ◽  
Shan Li ◽  
...  
Keyword(s):  
Isoelectric Focusing ◽  
Free Flow ◽  
Preparative Separation ◽  
Separation Of Proteins

Free-flow isoelectric focusing microfluidic device with glass coating by sol–gel methods

2009 ◽  
Vol 9 (2) ◽  
pp. e66-e70 ◽  
Author(s):  
Kwang Suk Yang ◽  
Philippe Clementz ◽  
Tae Jung Park ◽  
Seok Jae Lee ◽  
Jong Pil Park ◽  
...  
Keyword(s):  
Isoelectric Focusing ◽  
Microfluidic Device ◽  
Sol Gel ◽  
Free Flow ◽  
Glass Coating

scholarly journals 10 000-fold concentration increase of the biomarker cardiac troponin I in a reducing union microfluidic chip using cationic isotachophoresis

Lab on a Chip ◽  
2011 ◽  
Vol 11 (5) ◽  
pp. 890 ◽  
Author(s):  
Danny Bottenus ◽  
Talukder Zaki Jubery ◽  
Yexin Ouyang ◽  
Wen-Ji Dong ◽  
Prashanta Dutta ◽  
...  
Keyword(s):  
Microfluidic Chip ◽  
Cardiac Troponin ◽  
Troponin I ◽  
Cardiac Troponin I ◽  
Concentration Increase

Cardiac troponin I in patients with acute upper and lower limb ischemia

VASA ◽  
2008 ◽  
Vol 37 (4) ◽  
pp. 327-332 ◽  
Author(s):  
Koutouzis ◽  
Sfyroeras ◽  
Moulakakis ◽  
Kontaras ◽  
Nikolaou ◽  
...  
Keyword(s):  
Upper Limb ◽  
Lower Limb ◽  
Cardiac Troponin ◽  
Cardiac Involvement ◽  
Troponin I ◽  
Limb Ischemia ◽  
Elevated Troponin ◽  
Troponin Elevation ◽  
Lower Limb Ischemia ◽  
Ischemia Group

Background: The aim of this study was to investigate the presence, etiology and clinical significance of elevated troponin I in patients with acute upper or lower limb ischemia. The high sensitivity and specificity of cardiac troponin for the diagnosis of myocardial cell damage suggested a significant role for troponin in the patients investigated for this condition. The initial enthusiasm for the diagnostic potential of troponin was limited by the discovery that elevated cardiac troponin levels are also observed in conditions other than acute myocardial infarction, even conditions without obvious cardiac involvement. Patients and Methods: 71 consecutive patients participated in this study. 31 (44%) of them were men and mean age was 75.4 ± 10.3 years (range 44–92 years). 60 (85%) patients had acute lower limb ischemia and the remaining (11; 15%) had acute upper limb ischemia. Serial creatine kinase (CK), isoenzyme MB (CK-MB) and troponin I measurements were performed in all patients. Results: 33 (46%) patients had elevated peak troponin I (> 0.2 ng/ml) levels, all from the lower limb ischemia group (33/60 vs. 0/11 from the acute upper limb ischemia group; p = 0.04). Patients with lower limb ischemia had higher peak troponin I values than patients with upper limb ischemia (0.97 ± 2.3 [range 0.01–12.1] ng/ml vs. 0.04 ± 0.04 [0.01–0.14] ng/ml respectively; p = 0.003), higher peak CK values (2504 ± 7409 [range 42–45 940] U/ml vs. 340 ± 775 [range 34–2403] U/ml, p = 0.002, respectively, in the two groups) and peak CK-MB values (59.4 ± 84.5 [range 12–480] U/ml vs. 21.2 ± 9.1 [range 12–39] U/ml, respectively, in the two groups; p = 0.04). Peak cardiac troponin I levels were correlated with peak CK and CK-MB values. Conclusions: Patients with lower limb ischemia often have elevated troponin I without a primary cardiac source; this was not observed in patients presenting with acute upper limb ischemia. It is very important for these critically ill patients to focus on the main problem of acute limb ischemia and to attempt to treat the patient rather than the troponin elevation per se. Cardiac troponin elevation should not prevent physicians from providing immediate treatment for limb ischaemia to these patients, espescially when signs, symptoms and electrocardiographic findings preclude acute cardiac involvement.

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