**2.1 Quality of agarose**

In Asian countries, agar is widely known as an ingredient in foods and/or desserts (e.g. mitsumame, yokan, and so on in Japan). Agar is also a well-known gelling reagent for bacteria medium.

"Agarose" and "agar" are sold as different merchandises, but the origin of them is the same; both are made from the same seaweed. It can be said that agar for bacteria medium is a partially and roughly purified form of sea weeds and is of lower quality than agarose for electrophoresis.

In my experience, agar for bacteria medium is quite suitable for a gel electrophoresis reagent. INA AGAR® BA-30 (Ina Food Industry Co., Ltd. (Nagano, Japan)—Funakoshi Co., Ltd. (Tokyo, Japan)) (**Figure 1**, left) is an agar of which grade is for bacteria, but its quality is very good for electrophoresis. The cost for this reagent goes to about 1/5 of standard agarose for electrophoresis. Moreover, Ina agar S-7 (Ina Food Industry Co., Ltd. (Nagano, Japan)) (**Figure 1**, right) is an agar

#### **Figure 1.**

*Agars for not electrophoresis but other use. Left, INA AGAR BA-30 for bacteria medium. Right, INA S-7 agar for cooking.*
