**3. Electrophoresis buffer**

electrophoresis, and (c) soak the gel in the reagent buffer after electrophoresis (**Figure 4**). In (a) and (b), a photograph of the gel can be taken with a gel tray, when the tray is clear. In such a situation, a low gel strength does not disturb electrophoresis and DNA visualization. Based on these reasons, a low gel strength seems not a too much annoying point when simply doing electrophoresis and taking

*Scheme for staining and visualizing of DNA in agarose gel electrophoresis.*

*Analytical Chemistry - Advancement, Perspectives and Applications*

*Recycled gel (1% weight per volume) was applied to the electrophoresis.*

It is known that used agarose gel is reusable again and again. Recycling of agarose after electrophoresis is very effective for cost-saving. Several reports are published [13, 14], in which used agarose gels are simply boiled and poured to a gel tray. After cooling to make the recycle gel solid, the recycled gel is enough for applying another electrophoresis. On the other hand, the DNA staining reagent (such as EtBr) still remains in the used agarose gel. EtBr is well known as toxic mutagen [15, 16], so when used and stained gel is boiled, toxic fumes containing

photographs.

**Figure 5.**

**174**

**Figure 4.**

**2.2 Recycling and reusing of agarose**

The most standard buffer for agarose gel electrophoresis is TAE buffer (tris, acetic acid, EDTA). TBE (tris, boric acid, EDTA) is the second major buffer. It is said that TBE has an advantage to fractionate small length DNA; in an old sequence analysis, a combination of acrylamide gel and TBE buffer was a standard condition.

When TAE is compared with TBE, the cost of TBE is higher than TAE. This is because of the difference of the price of acetic acid and boric acid.

For RNA electrophoresis, MOPS buffer (MOPS, sodium acetate and EDTA) is another standard, although this buffer is much expensive. Anyhow, daily agarose gel electrophoresis is achieved in a condition of using TAE in standard.

Yet another electrophoresis buffer is SB buffer, which is obtained from sodium borate. The vast majority of SB buffer is the cost, 1/4 of TAE and 1/10 of TBE [18].

In my experience, DNA is well migrated and fractionated in the agarose gel electrophoresis with SB buffer, although small but many air cavities appeared after finishing the electrophoresis. The cavities do not exist when starting the electrophoresis, but they do appear several ten minutes after switching on and/or staining the gel after electrophoresis (**Figure 6**).

#### **3.1 Concentration of buffer**

It is a very simple and effective idea of cost-saving that dilution of the buffer is available or not. If 1/2 dilution is available, the cost also will be 1/2. In my experience, 0.5 TAE buffer works fine (**Figure 7**).

**Figure 6.** *SB buffer resulted in small but many air cavities in the gel.*

**Figure 7.** *Agarose gel electrophoresis with 0.5% TAE.*

A low concentration of ions in the buffer results in higher resistance in an electric circuit, which leads to heating of the buffer. Therefore, too much dilution of the buffer might result in boiling of buffer and melting of agarose gel.

*4.1.1 Making DIY buffer tank*

*commercial buffer tank.*

electrophoresis (**Figure 9**).

*4.1.2 Electrodes*

**Figure 10.**

**177**

**Figure 9.**

A plastic basket in variety store (so-called 100-yen shops, 99 cents store, Dollar store, etc.) is good enough for electrophoresis tank. Plastic tape is put on the basal plane in three- to fourfold repeatedly, which works as a stopper of the gel during

*DIY buffer tank for agarose gel electrophoresis. Note that the basket has a flat bottom, unlike a standard*

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

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

Although carbon stick like a lead of a pencil works as an electrode, stainless steel wire in hardware stores is a good choice of electrodes for agarose gel electrophoresis. No expensive metal is needed; almost the cheapest one will be worth testing. Wireframe of 1-2 mm in diameter leads to a good result. Wires are run at the

bottom corner of the tank, simply put by mending tape (**Figure 10**).

*An inexpensive stainless wire as electrodes of electrophoresis tank. This wire is 1.2 mm in diameter.*
