Document Detail


Magnetic-based microfluidic platform for biomolecular separation.
MedLine Citation:
PMID:  16688574     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
A novel microfluidic platform for manipulation of micro/nano magnetic particles was designed, fabricated and tested for applications dealing with biomolecular separation. Recently, magnetic immunomagnetic cell separation has attracted a noticeable attention due to the high selectivity of such separation methods. Strong magnetic field gradients can be developed along the entire wire, and the miniaturized size of these current-carrying conductors strongly enhances the magnetic field gradient and therefore produces large, tunable and localized magnetic forces that can be applied on magnetic particles and confine them in very small spots. Further increases in the values of the generated magnetic field gradients can be achieved by employing miniaturized ferromagnetic structures (pillars) which can be magnetized by an external magnetic field or by micro-coils on the same chip. In this study, we demonstrate magnetic beads trapping, concentration, transportation and sensing in a liquid sample under continuous flow by employing high magnetic field gradients generated by novel multi-functional magnetic micro-devices. Each individual magnetic micro-device consists of the following components: 1. Cu micro-coils array embedded in the silicon substrate with high aspect ratio conductors for efficient magnetic field generation 2. Magnetic pillar(s) made of the magnetic alloy NiCoP for magnetic field focusing and magnetic field gradient enhancement. Each pillar is magnetized by its corresponding coil 3. Integrated sensing coil for magnetic beads detection 4. Microfluidic chamber containing all the previous components. Magnetic fields of about 0.1 T and field gradients of around 300 T/cm have been achieved, which allowed to develop a magnetic force of 3 x 10(-9) N on a magnetic particle with radius of 1 mum. This force is large enough to trap/move this particle as the required force to affect such particles in a liquid sample is on the order of approximately pN. Trapping rates of up to 80% were achieved. Furthermore, different micro-coil designs were realized which allowed various movement modes and with different step-sizes. These results demonstrate that such devices incorporated within a microfluidic system can provide significantly improved spatial resolution and force magnitude for quick, efficient and highly selective magnetic trapping, separation and transportation, and as such they are an excellent solution for miniaturized mu-total analysis systems.
Authors:
Qasem Ramadan; Victor Samper; Daniel Poenar; Chen Yu
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Publication Detail:
Type:  Evaluation Studies; Journal Article    
Journal Detail:
Title:  Biomedical microdevices     Volume:  8     ISSN:  1387-2176     ISO Abbreviation:  Biomed Microdevices     Publication Date:  2006 Jun 
Date Detail:
Created Date:  2006-05-11     Completed Date:  2006-07-27     Revised Date:  2009-11-03    
Medline Journal Info:
Nlm Unique ID:  100887374     Medline TA:  Biomed Microdevices     Country:  United States    
Other Details:
Languages:  eng     Pagination:  151-8     Citation Subset:  IM    
Affiliation:
Bioelectronics & BioMEMS Program, Institute of Microelectronics, 11 Science Park Road, Singapore, 117685. qasemr@ime.a-star.edu.sg
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MeSH Terms
Descriptor/Qualifier:
Biopolymers / isolation & purification*,  radiation effects*
Complex Mixtures / isolation & purification*
Equipment Design
Equipment Failure Analysis
Flow Injection Analysis / instrumentation*,  methods
Immunomagnetic Separation / instrumentation*,  methods
Magnetics*
Microfluidic Analytical Techniques / instrumentation*
Miniaturization
Chemical
Reg. No./Substance:
0/Biopolymers; 0/Complex Mixtures

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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