Download IMMUNOASSAY UTILIZING MAGNETIC BEADS FOR RAPIDVIRUS

IMMUNOASSAY
UTILIZING
MAGNETIC BEADS FOR RAPIDVIRUS
DETECTION IN THE MICROFLUIDIC
FLOW CYTOMETER SYSTEM
Sung-Yi Yang, Kang-Yi Lien, Kao-Jean Huang,
Huan-Yao Lei, Gwo-Bin Lee
National Cheng Kung University, Tainan Taiwan
uTAS2007
Professor : Liu, Cheng-Hsien
Student : Olof Sterner
AGENDA
1.
2.
3.
4.
5.
Introduction
Design and Fabrication
Results
Conclusion
Discussion
INTRODUCTION

In this article:
Integrated fluid chip for rapid virus
identification.
 Fluid movement is performed by
micro circulatory pump driven by
airpressure.
 Magnetic beads covered with specific
antibodies.
 Detection of virus is made through
fluorescence by a PMT module.

INTRODUCTION

Current viruses threatening mankind








Influenza
Hepatitis
HIV
Dengue fever
Ebola
Yellow Fever
Etc
Treatment for viral infections are far behind
those of bacterial infections

Quick diagnosis crucial
DESIGN AND FABRICATION

Magnetic beads
Covered in specific antibodies
toward a certain virus
 Virus particle functions as
antigen and binds specifically
to the primary antibody on the
magnetic bead.
 Secondary antibody towards
the same virus but targeting a
different epitope binds to the
virus and carries a fluorescent
compound.

DESIGN AND FABRICATION

Main detection principle
1. Magnetic beads with
primary target
antibody
2. Target antigen is
added (Virus)
3. Secondary fluorescent
antibodies is added
4. Fluidic focusing
5. Detection by means of
fluorescense
DESIGN AND FABRICATION

The integrated flow cytometer system
A
B
C
Dimensions : 46 mm * 66 mm * 5 mm
DESIGN AND FABRICATION
A
– Virus attachement to magnetic beads.
1. Injection of bio sample and
magnetic beads
2. Introduction of sec fluorescent
antibodies
3. Mixing with rotary microfluidic
pump
DESIGN AND FABRICATION
 Airpressure
driven rotary microfluidic
pump
Biomed Microdevices (2007) 9:545–554
DOI 10.1007/s10544-007-9062-6
DESIGN AND FABRICATION

B – Washing and Pretreatment
Purification and enrichment of virus samples utilizing magnetic
beads on a microfluidic system, Lab Chip, DOI: 10.1039/b700516d,
(2007)
1. Cu microcoils induced magnetic field attracts
magnetic beads
2. Washing with buffer
3. Release of magnetic beads
(Flow generated by rotary microfluidic pump)
DESIGN AND FABRICATION

C – Fluid focusing, detection and sorting
1. Sheath flow injection
2. Flow from rotary microfluidic pump for fluid
focusing
3. Detection by PMT module
4. Sorting of magnetic beads using feedback signals
from PMT
5. Collection of magnetic beads
(Flow generated by rotary microfluidic pump
RESULTS

Evaluation of:




Pumping rate vs driving frequency of
circulatory pump
Magnetic field and Temperatur vs Applied
current
Fluorescence signal amplitude vs time
Virus detection limit
RESULTS
Pumping rate vs
driving frequence of
circulatory pump
Magnetic field and
Temperature in focusing vs
Applied current
RESULTS
Signal amplitude from fluorescence
measurement vs time
Singal to Noise ratio of 30
Minimum
concentration
of 104 pfu/ml of
Dengue virus
could be
detected.
RT-PCR has
detection limit of
~1 pfu/ml
CONCLUSION

Design for rapid virus diagnosis
has been proposed
DISCUSSION
Easy principle, sandwich
immunoassay is well documented
 Gate design is not included in
article
 Sensitivity needs to be enchanced

REFERENCES
Lab Chip, 2007, 7, 868–875, DOI:
10.1039/b700516d
 Biomed Microdevices (2007) 9:545–554 DOI
10.1007/s10544-007-9062-6

TACK
!