I MMUNOASSAY 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

A GENDA 1. Introduction 2. Design and Fabrication 3. Results 4. Conclusion 5. Discussion

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. I NTRODUCTION

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 I NTRODUCTION

D ESIGN AND F ABRICATION 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.

D ESIGN AND F ABRICATION 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

D ESIGN AND F ABRICATION The integrated flow cytometer system A B C Dimensions : 46 mm * 66 mm * 5 mm

D ESIGN AND F ABRICATION 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

D ESIGN AND F ABRICATION Airpressure driven rotary microfluidic pump Biomed Microdevices (2007) 9:545–554 DOI /s

D ESIGN AND F ABRICATION B – Washing and Pretreatment 1.Cu microcoils induced magnetic field attracts magnetic beads 2.Washing with buffer 3.Release of magnetic beads (Flow generated by rotary microfluidic pump) Purification and enrichment of virus samples utilizing magnetic beads on a microfluidic system, Lab Chip, DOI: /b700516d, (2007)

D ESIGN AND F ABRICATION 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

R ESULTS 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

R ESULTS Pumping rate vs driving frequence of circulatory pump Magnetic field and Temperature in focusing vs Applied current

R ESULTS Signal amplitude from fluorescence measurement vs time Minimum concentration of 10 4 pfu/ml of Dengue virus could be detected. RT-PCR has detection limit of ~1 pfu/ml Singal to Noise ratio of 30

C ONCLUSION Design for rapid virus diagnosis has been proposed

D ISCUSSION Easy principle, sandwich immunoassay is well documented Gate design is not included in article Sensitivity needs to be enchanced

R EFERENCES Lab Chip, 2007, 7, 868–875, DOI: /b700516d Biomed Microdevices (2007) 9:545–554 DOI /s

TACK !