Sanford-Burnham Medical Research Institute filed a patent application related to compositions and methods for selectively targeting an endometriosis cell, and also compositions and methods for treating endometriosis. Sanford utilized a PCT filing and entered the United States from its PCT application. Under this scenario, the US Patent and Trademark Office must examine all of the claims of the patent as long as they have "Unity of Invention." If the claims do not have unity, then the Examiner can require the application to pick a defined subset of claims and the applicant must file one or more divisional applications to pursue unelected claims (which obviously can significantly increase costs).
Examiners often issue improper restrictions, but rarely learn of their own errors because so few applicants actually go through the process of fighting the restriction. This is because conventional wisdom is that the extra cost of fighting is outweighed by the low chance of success. However, some applicants do fight, and win, restrictions.
Here, in Sanford's application (US 14/897,757), the Applicant specifically amended the claims responsive to the restriction to fall within one of the defined exceptions in the examination guidelines. Specifically, the Guidelines from WIPO provide the following example:

Example 39: Protein and its Encoding DNA

Claim 1: Isolated protein X having SEQ ID NO: 1.

Claim 2: Isolated DNA molecule encoding protein X of claim 1.

(Some Authorities presume that a claimed biological molecule is in isolated form and therefore do not require the claim to explicitly include the term “isolated” as above.)

The disclosure teaches that protein X is an interleukin-1, a soluble cytokine involved in the activation of lymphocytes. The disclosure also sets forth a DNA molecule having SEQ ID NO: 2 that encodes SEQ ID NO: 1.

There is no prior art. The claimed DNA molecule encodes protein X, and therefore protein X and the DNA encoding protein X share a corresponding technical feature. Consequently, the claims have unity of invention (a priori).

Because protein X makes a contribution over the prior art, protein X and the DNA encoding protein X share a special technical feature. If an alternative DNA claim was presented that encompassed a DNA molecule that did not encode protein X, some Authorities might find that the claims did not share the same or corresponding technical feature and therefore lacked unity. Examples of such a claim follow:

Isolated DNA molecule encoding protein X, or a DNA fragment thereof.

Isolated DNA molecule having SEQ ID NO: 2, or DNA molecules which hybridise to

SEQ ID NO: 2 under stringent conditions. If prior art existed teaching either protein X or the DNA encoding protein X, some Authorities might find that the same or corresponding technical feature did not make a contribution over the prior art, that is, was not a special technical feature, and therefore unity was lacking (a posteriori).

Despite the fact that the applicant amended the claims to specifically fall within this exception, the Examiner responded that "[l]ack of Unity, once broken, cannot be brought back into unity."
The applicant correctly pointed out that there is no such rule, and petitioned the Office to have the restriction removed. The Applicant was successful as the Office confirmed that:







So, if you have an Examiner refusing to follow the guidlines and responding with fanciful ideas as to the law, consider a petition rather than giving in and paying more government fees than you should.