Yeastern Biotech Co., Ltd. owns the patent of ECOS™ technology (protocol) exclusively in USA, UK, Taiwan, and France (Patent No. US 6,864,088; GB 2383582; I 229696; FR 2832727, etc.). Under the protection of this patent, Yeastern Biotech is the only company that has the right to use the protocol with the claims that transformation with our ECOS™ chemically competent cells can be finished within one minute and SOC is not needed. If anyone intends to sell competent cells that use ECOS™ protocol or its similar version, please contact our headquarters in Taiwan for licensing.

Each lot of competent cells has to pass three quality control tests before shipping:

1. Efficiency test: each batch of ECOS™ should meet the claimed transformation efficiency at the time of production using Protocol 4 (Page 3-3) and supercoiled pUC19 DNA.
2. Contamination test: competent cells were plated directly on ampicillin plates without being transformed. To pass the test, no colonies should be seen after overnight incubation.
3. A-complementation test: this test is performed for all ECOS™ competent cells except for ECOS™ 21(DE3) and ECOS™ 2163. To pass the test, the ratio of white colonies over the total colonies should be less than 3%