*4.2.1 DIY power supply*

To make half-wave or full-wave rectified current is not so difficult. **Figure 12** is a diagram showing full-wave rectification from alternating current. Four diodes are needed in this diagram, and they are substituted by one Graetz bridge.

**Figure 12.**

*A simple circuit diagram of full-wave rectification for agarose gel electrophoresis.*

**Figure 13.** *A DIY power supply based on a diagram of* **Figure 12***.*

One avoidable notice is that copper is included in the wire as a component of wire. Copper is thought to be toxic, and it is ionized and flow out into the buffer during electrophoresis. Such a wire should be avoided, and it can be easily and clearly determined if copper is ionized because copper ion turns the buffer blue.

*An alternating current (a), half-wave rectified current (b), full-wave rectified current (c), and a true direct current. (b) and (c) are enough for doing agarose gel electrophoresis, and true direct current like (d) is not*

*Analytical Chemistry - Advancement, Perspectives and Applications*

**Figure 11.**

*needed.*

**178**

buffer tank and power supply in this manuscript will also be able to work in RNA electrophoresis, because of the same principle of the electrophoresis of nucleic

*Cost-Effective Technical Tips for Agarose Gel Electrophoresis of Deoxyribonucleic Acid*

I thank Mr. Masayuki Goshima for technical advice and Ms. Haruka Yano and

Department of Applied Biochemistry, School of Engineering, Tokai University,

© 2020 The Author(s). Licensee IntechOpen. This chapter is distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/ by/3.0), which permits unrestricted use, distribution, and reproduction in any medium,

\*Address all correspondence to: noboru.sasagawa@tokai-u.jp

provided the original work is properly cited.

acids.

**Acknowledgements**

**Conflict of interest**

**Author details**

Noboru Sasagawa

Kanagawa, Japan

**181**

Mr. Yuta Yamada for discussing about experiments.

*DOI: http://dx.doi.org/10.5772/intechopen.93439*

The authors declare no conflict of interest.

#### **Figure 14.**

*A close view of the DIY power supply (***Figure 13***). An inexpensive Graetz bridge (AM1510) is used in the supply.*

**Figure 13** is an example of DIY power supply, which is based on the diagram of **Figure 12**. **Figure 14** is a close view of the same DIY power supply, in which only one Graetz bridge is used. A fuse is incorporated in this supply for safety.
