Examination of Biological Sequence Claims in China

Dr. Peng Jing, Jichao Zhu | Jul 30, 2020

The biotechnology industry has steadily become an important part of the economy in recent years. The development of the biotech industry has been proclaimed as “National Development Strategy” and has been considered as an increasingly important part of the Strategic Emerging Industry of China and many other countries. Remarkable technological advances have been achieved as a result of increased investment and support in this industry. A large number of patent applications have been filed for technical breakthroughs and innovations in this field and many of them have claims for nucleic acid sequences, amino acid sequences, genes, primers, probes, biomarkers, enzymes, antibodies, or polypeptides. However, the scope of claims to be granted and the scope of description needed have always been hot topics and very controversial issues. This article briefly summarized the examination guidelines and patenting strategies for biological sequence claims in China.

Part II, Chapter 10, Section 9.3 in the Guidelines for Patent Examination (2010) has specified drafting principles for claims relating to biological sequences. With reference to these principles, a biological sequence is generally claimed in the following ways:

(1) A biological sequence can be defined directly. Generally, a closed phrase (“consisting of”) should be used. A gene sequence can optionally be defined with its encoded amino acid sequence;

(2) When a protein with a special function, or a gene encoding a protein with a special function, a biological sequence can be defined, in combination with the function, by specifying homology, identity, substitution, deletion or addition, or hybridization under strict conditions. However, such definitions are only allowable on the condition that the corresponding biological sequences within the claimed scope are exemplified in the description, and the description discloses the technical means for preparing such biological sequences and demonstrating their functions.

Pursuant to the guideline above, Chinese examiners generally allow biological sequence claims that are relatively narrow. For example:

A PCT application related to homolactic thermophilic bacilli separately entered national phases in China, the US, EPO, and Japan. As shown in the table below, responses from different patent offices and the scopes of granted claims (defined by "homology + function") are quite different.





Examination process

The feature "at least 95% identity" is not supported by the description.

The feature "at least 80% identity" is not supported by the description.

The definition relating to sequence homology is not questioned.

The feature "at least 80% identity" is not supported by the description.

Examination result

In combination with a function definition, the feature "at least 98% identity" is accepted to be supported by the description.

The feature "at least 90% identity" is accepted.

The feature "at least 80% identity" is accepted.

The feature "at least 90% identity" is accepted.


Obviously, the description requirement from CNIPA is the highest one among these four offices in this case.

According to the Chinese patent law, if a person skilled in the art can reasonably expect that all biological sequences within the scope of claims have the same property or function based on the description, such claims will be considered to be supported by the description. Therefore, to get broader claims, it is highly suggested that the patent attorney draft the specification by a layer-by-layer approach so that different scopes of technical solutions can be protected.

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