Laboratory Methods in Microfluidics

By Basant Giri

Laboratory Methods in Microfluidics features a range of lab methods and techniques necessary to fully understand microfluidic technology applications. Microfluidics deals with the manipulation of small volumes of fluids at sub-millimeter scale domain channels. This exciting new field is becoming an increasingly popular subject both for research and education in various disciplines of science, including chemistry, chemical engineering and environmental science.

The unique properties of microfluidic technologies, such as rapid sample processing and precise control of fluids in assay have made them attractive candidates to replace traditional experimental approaches.

Practical for students, instructors, and researchers, this book provides a much-needed, comprehensive new laboratory reference in this rapidly growing and exciting new field of research.

• Provides a number of detailed methods and instructions for experiments in microfluidics
• Features an appendix that highlights several standard laboratory techniques, including reagent preparation plus a list of materials vendors for quick reference
• Authored by a microfluidics expert with nearly a decade of research on the subject

• Language: English
• Publisher: Elsevier Science
• Release date: May 15, 2017
• ISBN: 9780128132364

Basant Giri

Earned his doctorate in Analytical Chemistry from the University of Wyoming in 2013, where he developed microfluidic ELISA methods as part of his dissertation. Dr. Giri has been conducting research and instructing in the field of microfluidics for the past six years. He is currently a research scientist at Kathmandu Institute of Applied Sciences in Kathmandu, Nepal. His research interests involve developing microfluidics methods for various applications especially suitable for low resource settings

Book preview

Laboratory Methods in Microfluidics

Basant Giri

Center for Analytical Sciences, Kathmandu Institute of Applied Sciences, Kathmandu, Nepal

Table of Contents

Cover image

Title page

Copyright

About the Author

Preface

Key features

Acknowledgments

1. Introduction to Microfluidics

Abstract

1.1 Background

1.2 Frequently Used Microfluidic Terms

1.3 Assessment Questions

References

2. Fabrication of a Glass Microfluidic Device

Abstract

2.1 Background

2.2 Microfluidic Device Design

2.3 Chemicals and Supplies

2.4 Hazards

2.5 Experimental Procedure

2.6 Additional Notes

2.7 Assessment Questions

References

3. Fabrication of a Paper Microfluidic Device for Blood-Plasma Separation

Abstract

3.1 Background

3.2 Microfluidic Device Design

3.3 Chemicals and Supplies

3.4 Hazards

3.5 Experimental Procedure

3.6 Additional Notes

3.7 Assessment Questions

References

4. Fabrication and Testing of a PDMS Microchip

Abstract

4.1 Background

4.2 Design of the Microfluidic Device

4.3 Chemicals and Supplies

4.4 Hazards

4.5 Experimental Procedure

4.6 Additional Notes

4.7 Assessment Questions

References

5. Determination of Electroosmotic Flow in a Glass Microfluidic Device Using a Neutral Marker

Abstract

5.1 Background

5.2 Microfluidic Device Design

5.3 Chemicals and Supplies

5.4 Hazards

5.5 Experimental Procedure

5.6 Additional Notes

References

6. Electrophoretic Separation in a Microchannel

Abstract

6.1 Background

6.2 Design of the Microfluidic Device

6.3 Chemicals and Supplies

6.4 Hazards

6.5 Experimental Procedure

6.6 Additional Notes

6.7 Assessment Questions

References

7. A Simple Experiment for the Study of Droplet Microfluidics

Abstract

7.1 Background

7.2 Microfluidic Device Design

7.3 Chemicals and Supplies

7.4 Hazards

7.5 Experimental Procedure

7.6 Additional Notes

7.7 Assessment Questions

References

8. Laminar Flow and Diffusion in a Microchannel

Abstract

8.1 Background

8.2 Microfluidic Device Design

8.3 Chemicals and Supplies

8.4 Hazards

8.5 Experimental Procedure

8.6 Additional Notes

8.7 Assessment Questions

References

9. Beer’s Law Using a Smartphone and Paper Device

Abstract

9.1 Background

9.2 Microfluidic Device Design

9.3 Chemicals and Supplies

9.4 Hazards

9.5 Experimental Procedure

9.6 Additional Notes

9.7 Assessment Questions

References

10. Acid–Base Titrations on Paper

Abstract

10.1 Background

10.2 Design of the Microfluidic Device

10.3 Chemicals and Supplies

10.4 Hazards

10.5 Experimental Procedure

10.6 Additional Notes

10.7 Assessment Questions

References

11. Simultaneous Determination of Protein and Glucose in Urine Sample Using a Paper-Based Bioanalytical Device

Abstract

11.1 Background

11.2 Microfluidic Device Design

11.3 Chemicals and Supplies

11.4 Hazards

11.5 Experimental Procedure

11.6 Additional Notes

11.7 Assessment Questions

References

12. Quantitative Determination of Total Amino Acids in Tea Using Paper Microfluidics and a Smartphone

Abstract

12.1 Background

12.2 Microfluidic Device Design

12.3 Chemicals and Supplies

12.4 Hazards

12.5 Experimental Procedure

12.6 Additional Notes

12.7 Assessment Questions

References

13. Determination of Nitrite Ions in Water Using Paper Analytical Device

Abstract

13.1 Background

13.2 Microfluidic Device Design

13.3 Chemicals and Supplies

13.4 Hazards

13.5 Experimental Procedure

13.6 Additional Notes

13.7 Assessment Questions

References

14. Colorimetric Determination of Multiple Metal Ions on µPAD

Abstract

14.1 Background

14.2 Microfluidic Device Design

14.3 Chemicals and Supplies

14.4 Hazards

14.5 Experimental Procedure

14.6 Additional Notes

14.7 Assessment Questions

References

15. Analysis of a Mixture of Paracetamol and 4-Aminophenol in a Paper-Based Microfluidic Device

Abstract

15.1 Background

15.2 Microfluidic Device Design

15.3 Chemicals and Supplies

15.4 Hazards

15.5 Experimental Procedure

15.6 Additional Notes

15.7 Assessment Question

References

16. Synthesis of Gold Nanoparticles on Microchip

Abstract

16.1 Background

16.2 Microfluidic Device Design

16.3 Chemicals and Supplies

16.4 Hazards

16.5 Experimental Procedure

16.6 Additional Notes

16.7 Assessment Questions

References

17. Flow Synthesis of Organic Dye on Microchip

Abstract

17.1 Background

17.2 Design of the Microfluidic Device

17.3 Chemicals and Supplies

17.4 Hazards

17.5 Experimental Procedure

17.6 Additional Notes

17.7 Assessment Questions

References

18. Protein Immobilization on a Glass Microfluidic Channel

Abstract

18.1 Background

18.2 Microfluidic Device Design

18.3 Chemicals and Supplies

18.4 Hazards

18.5 Experimental Procedure

18.6 Additional Notes

18.7 Assessment Question

References

19. Microfluidic Enzyme-Linked Immunosorbent Assay

Abstract

19.1 Background

19.2 Microfluidic Device Design

19.3 Chemicals and Supplies

19.4 Hazards

19.5 Experimental Procedure

19.6 Additional Notes

19.7 Assessment Questions

References

Glossary

Appendices

Appendix I Keeping Your Lab Notebook and Writing Lab Report

Appendix II Preparation of Selected Reagents and Solutions

Appendix III Use and Calibration of Micropipettes

Appendix IV Statistical Treatment of Data

Appendix V Installation and Use of ImageJ Software

Appendix VI Where to Buy: Vendors and Service Provider Information

Appendix VII CAS Registry Numbers

References

Index

Copyright

Elsevier

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The Boulevard, Langford Lane, Kidlington, Oxford OX5 1GB, United Kingdom

50 Hampshire Street, 5th Floor, Cambridge, MA 02139, United States

Copyright © 2017 Elsevier Inc. All rights reserved.

No part of this publication may be reproduced or transmitted in any form or by any means, electronic or mechanical, including photocopying, recording, or any information storage and retrieval system, without permission in writing from the publisher. Details on how to seek permission, further information about the Publisher’s permissions policies and our arrangements with organizations such as the Copyright Clearance Center and the Copyright Licensing Agency, can be found at our website: www.elsevier.com/permissions.

This book and the individual contributions contained in it are protected under copyright by the Publisher (other than as may be noted herein).

Notices

Knowledge and best practice in this field are constantly changing. As new research and experience broaden our understanding, changes in research methods, professional practices, or medical treatment may become necessary.

Practitioners and researchers must always rely on their own experience and knowledge in evaluating and using any information, methods, compounds, or experiments described herein. In using such information or methods they should be mindful of their own safety and the safety of others, including parties for whom they have a professional responsibility.

To the fullest extent of the law, neither the Publisher nor the authors, contributors, or editors, assume any liability for any injury and/or damage to persons or property as a matter of products liability, negligence or otherwise, or from any use or operation of any methods, products, instructions, or ideas contained in the material herein.

British Library Cataloguing-in-Publication Data

A catalogue record for this book is available from the British Library

Library of Congress Cataloging-in-Publication Data

A catalog record for this book is available from the Library of Congress

ISBN: 978-0-12-813235-7

For Information on all Elsevier publications visit our website at https://www.elsevier.com/books-and-journals

Publisher: John Fedor

Acquisition Editor: John Fedor

Editorial Project Manager: Emily Thomson

Production Project Manager: Anitha Sivaraj

Designer: Miles Hitchen

Typeset by MPS Limited, Chennai, India

About the Author

Basant Giri received BSc and MSc degrees in Chemistry from Tribhuvan University, Kathmandu, Nepal, a second MS degree in Chemistry from the Oregon State University, Corvallis, USA, and a PhD degree in Chemistry from the University of Wyoming, Laramie, USA. After working as a research fellow at Nepal Academy of Science and Technology, Nepal for six months, Dr. Giri cofounded the Kathmandu Institute of Applied Sciences in Kathmandu, Nepal. Currently he works as a scientist at the Center for Analytical Sciences at the same institute. His research interests include development of low-cost analytical devices (e.g., paper microfluidics) for biological and environmental applications. He has several years of teaching experience at high school, undergraduate, and graduate levels in Nepal and the United States as faculty and teaching assistant, respectively. Dr. Giri has authored and coauthored a textbook on Nanoscience and Nanotechnology and several peer-reviewed research articles.

Preface

Basant Giri

Considering the increasing interest in microfluidics, Laboratory Methods in Microfluidics aims to fill the need for a laboratory book in this field.

Microfluidics is becoming an increasingly popular subject both in education and research. Many universities are now incorporating microfluidics in their courses to a greater or lesser extent along with experiments in the laboratory courses. Even though there are several textbooks covering this topic, there is currently no resource covering experimental procedures. This laboratory book aims to provide a number of detailed instructions for experiments in microfluidics intended for undergraduate and postgraduate courses in analytical chemistry, biochemistry, microbiology, biotechnology, environmental science, and engineering. Some experiments can even be implemented in high-school curriculum projects and experiments.

Most of the experiments described in this book have been adapted from research articles and the experience of the author while teaching undergraduate analytical chemistry labs. While care has been taken to ensure that the information in this book is correct, neither the author nor the publisher can accept responsibility for the outcome of the experimental procedures outlined in this book if not properly followed. The main aim of the book is to serve as an educational tool to prepare today’s students for the more demanding regimen of microfluidics. The experiments aim to provide practical experience in the application of classical and instrumental techniques incorporated in microfluidics. Each experiment includes background information including learning objectives and an overview of the principles behind the experiment, a list of materials and chemicals required, safety notes, step-by-step procedure, additional notes to instructor, assessment questions, and recommendations for further reading. The instructions for the experiments are so detailed that the measurements can, for the most part, be taken without the help of additional literature. With Laboratory Methods in Microfluidics instructors no longer have to refer to many journals and books to find the right procedures for their experiments. It is assumed that students are familiar with basic laboratory techniques and procedures in science before starting experiments described in this book. However, some basic practices are covered in the Appendix.

In conclusion, this book is a work in progress, and I encourage readers to submit ideas, suggestions, and comments for improvements or for new experiments. I hope you find this laboratory manual helpful in your study.

Key features

• 18 Standalone fine-tuned experiments

• Emphasizes fabrication of microfluidic devices and their and applications

• Experiments using commonly found materials to minimize the cost

• Assessment questions for each experiment

• Appropriate illustrations for each experiment

• Additional notes for instructors allowing them to customize the experiments

• Useful information about preparation of laboratory reagents in appendices

January, 2017

Acknowledgments

I am thankful to Dr. Harish Subedi of Western Nebraska Community College, Nebraska, Dr. Basu Panthi of Trinity University, Texas, and Dr. Lekh Adhikari of Rappahannock Community College, Virginia for providing input on the initial draft of this book. Likewise, I am thankful to Dr. Susma Giri (my wife), Mr. Ankit Pandeya, and Mr. Sagar Rayamajhi of Kathmandu Institute of Applied Sciences, Nepal for proofreading the manuscript.

I am grateful to my PhD advisor Dr. Debashis Dutta from the University of Wyoming, who introduced me to the field of microfluidics. Dr. Tristan Kinde of Sinclair Oil Corporation (then graduate student at Dutta group) helped me fabricate the glass microfluidic device during my early days as a PhD student. The lab methods described in this book such as fabrication of glass microfluidic device, enzyme assay, and microfluidic separation were initially developed for an instrumental analysis course by Dutta Lab at University of Wyoming.

I express my love and gratitude to my father Krishna and mother Dwarika for their love, support, patience, and sacrifice.

1

Introduction to Microfluidics

Abstract

This first chapter of Laboratory Methods in Microfluidics introduces microfluidics including fundamental features, advantages, and examples of commercial applications. The second part of the chapter includes a brief description of frequently used that may help to explain microfluidic phenomenon and the principles including laminar flow, electrokinetic flow, and separation resolution. Equations are given and described when necessary. In addition, some questions are listed that can be given for students assessment. The references provided at the end of the chapter may be used for further reading material.

Keywords

Lab-on-a-chip; μ-TAS; laminar flow; electrophoresis; paper-devices

1.1 Background

The field of microfluidics has been gaining popularity in the scientific community since its jumpstart about three decades ago. This multidisciplinary field has become a unique platform for chemistry, physics, biology, materials science, fluid mechanics, and engineering disciplines in terms of understanding both fundamentals and applications. Two other terms related to microfluidics are lab-on-a-chip and micrototal analysis systems, popularly known as μ-TAS. It is important to learn microfluidic experiments considering their potential in analytical applications and their advantages over conventional analytical systems. Incorporating microfluidics in teaching laboratories enables learning opportunities for undergraduate and graduate students, even high school students and independent researchers. As microfluidics require less amount of chemicals/reagents and generate less waste, universities could reduce the cost related to chemicals and waste disposal.

1.1.1 What is Microfluidics?

Microfluidics is the science that deals with the precise control and manipulation of small volumes of fluids in network of microchannels. Generally, micro means one of the following features: small volumes (µL, nL, pL, fL) and small size leading to low energy consumption and special microdomain effects. Small size means at least one dimension of the channel must be in the range of micrometers. The behavior of fluids at microscale can differ from macroscale behavior. Factors such as surface tension, energy dissipation, and fluidic resistance start to dominate the system at micro level. A microfluidic chip or device contains a network of microchannels, which are connected to the outside of the channel by inputs and outputs pierced through the chip. Such connections serve as an interface between the macro- and microworld. Through these holes, the liquids or gas are injected and removed from the microfluidic chip. The small size of microfluidic devices offers several advantages including less sample and reagent consumption, low cost, short analysis time, portability, etc.¹

Microfluidic technologies are not just for education and research. These technologies have now been incorporated into many commercial products. Inkjet printheads are an example of the most successful application of microfluidics.² Printers used to reproduce digital images produced by computers commonly use such inkjet printers. Other commercial products based on microfluidics include:

1. Agilent bioanalyzer: The bioanalyzer instrument provides platform for bioassays, based on electrophoresis and flow cytometry, of DNA, RNA, proteins and cells with less than four microliters of sample.³

2. HPLC-Chip/MS system: Produced by Agilent this system is based on microfluidic chip technology and is designed for nanospray liquid chromatography/mass spectrometry (LC/MS). According to the manufacturer, this system is robust, reliable, sensitive, and easy to use for biomarker discovery and validation, monoclonal antibody characterization, small-molecule analysis, phosphopeptide analysis, etc.⁴

3. Caliper LabChip platforms: Caliper of the PerkinElmer company has produced a number of LabChip devices/kits⁵ based on microfluidics involving both electrokinetic and pressure-driven flows. These devices can be used in bioassays for drug discovery applications such as small-molecule screening, fragment based screening, target specificity profiling, etc. The genomic DNA LabChip is used for DNA analysis.⁶

4. Point-of-care blood analyzers and other medical diagnostic platforms from companies including⁷ Abaxis, Abbott, Achira labs, Biosite, Biovitesse, Biolithic, Baebies, Boston Microfluidics, CardioMEMS, GenePOC, FluidMedix, Micro2Gen, Nanosphere, Nanomix, etc.

1.2 Frequently Used Microfluidic Terms

1.2.1 Laminar Flow

One of the important properties of fluid flow in the microdomain is laminar flow. In laminar or streamline flow, fluids flow side-by-side in parallel layers and do not necessarily mix unlike in turbulent type flow. Adjacent layers slide past