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Shoshi Inooka, Speaker at Chemical Engineering Conferences
President of Japan Association of Science Specialists, Japan
Title : Preparation of DNA Crown Cells (artifical cells) Using Eggs and Sphingosine-DNA


DNA crown cells are artificial cells in which the outside of the cells are covered with DNA; this class of cells is selfreplicating. Full application of DNA crown cells will require the development of techniques that are simple and scalable. To date, methods to obtain artificial cells that can replicate have been not established. Therefore, this presentation describes a detailed method for the preparation of these cells.


The required materials include sphingosine (Sph), DNA, adenosine, and eggs. Sph is formulated at 10 mM in 50% ethanol (10 mM). DNA (1.7 μg /μl) and adenosine (0.1 M) are formulated in distilled water; the use of distilled water for this purpose is key to this protocol. The edible chicken eggs are obtained from a local market.

Generalized method:

Step 1: Sph (90 μl) and DNA (40 μl) are mixed. The mixture is boiled for a few minutes and cooled in ice.

Step 2: Adenosine (300 μl) is added to the Sph-DNA mixtures.

Step 3: Sph-DNA/adenosine mixtures are injected within the egg white and the eggs then are incubated a 37°C.

After 7 days, DNA crown cells will have formed within the egg white.

This protocol permits the ready preparation of DNA crown cells (artificial cells) in essentially un-limited numbers.These cells can be generated with any of various sources of nucleic acid. In the original study, an extract of an Ascidian sea squirt was used. Subsequently, I discovered that adenosine was effective to form artificial cells and established the generalized method for preparing DNA crown cells described above. To date, I have successfully prepared DNA crown cells using DNA from Escherichia coli, Lactobacillus, human placenta, bovine meat and so on with the extract of an Ascidian sea squtri or adenosine.

A key aspect of the method described here is that the cells can be prepared with commercial reagents (Sph, DNA, and adenosine). Many kinds of DNA crown cells can be obtained and recovered from egg white. Thus, this protocol is expected to contribute to new research in the life sciences and to find application in the biotechnology industry. 


Shoshi Inooka has completed his PhD in Tohoku University in Sendai, Japan. Currently he is working as a President of nonprofit organization: Japan Association of Special Scientists and President of the Japan Academy of Applied Cell Biology.