Share this article:

Patents Court provides guidance on technical experts vs scientific advisers

By Angus Milne, Associate and James Simpson, Trainee Solicitor


The Patents Court has provided useful clarity regarding the different roles of technical experts and scientific advisers in English patent actions. We have summarised the Court’s guidance below. The judgment itself, in Hill v Touchlight Genetics Ltd [2024] EWHC 533 (Pat), can be found here.


The underlying dispute is a patent entitlement claim in the field of biotechnology. The Defendants, Touchlight, owns patents and patent applications relating to a synthetic DNA vector and its production. The Claimant, Dr. Hill, alleges that, before her employment with Touchlight, she had already made and disclosed to Touchlight inventions relevant to Touchlight’s patent family. The Claimant further alleges that she only assigned part of these inventions to Touchlight and therefore she remains entitled to ownership of the other part. Accordingly, the Claimant says she is entitled to be a joint proprietor of relevant patents and patent applications in Touchlight’s patent family.

The parties agreed that technical assistance would help the Court to resolve the claims, but disagreed on how best to achieve that end. The Claimant argued that the Court should appoint a scientific adviser only. The Defendants sought the exchange of expert evidence without an additional scientific adviser.

Roles of technical experts vs scientific advisers

Mellor J described the different roles of technical experts and scientific advisers as follows:

“The role of a scientific adviser and the role of technical expert evidence in patent proceedings have this in common: the purpose of both is to educate the Court in the relevant technology… However, there is a clear distinction between those roles: a scientific advisor is not there to address any technical disputes, that is the province of expert evidence, to the extent that expert evidence is appropriate and admissible”.

The Court considered how these roles had been utilised in previous cases, noting evidence from the Defendants that showed:

  • most scientific advisors had been appointed to assist appeal courts, and in almost all of those cases there was no scientific advisor at first instance, since the trial was conducted before one of the specialist Category 4 / Category 5 Patent Judges;
  • in the few cases where a scientific advisor was appointed to assist a first instance Judge, it was either because the case was complex but the Judge was not a Category 4 / Category 5 Patent Judge or because the case was especially complex, even for such a Judge;
  • in all cases where a scientific advisor was appointed, their role was to educate the Court in the relevant technology, in a non-partisan way, rather than to address any issue in the proceedings; and
  • in no case was a scientific advisor appointed without there being evidence from technical experts.

The Claimant did not dispute this evidence, but instead sought to differentiate this case on the basis that it was an entitlement dispute, which gave rise to very different issues to those in traditional patent actions (e.g. for infringement or invalidity). In particular, the Claimant noted that almost all entitlement disputes were decided in the UKIPO or in the High Court without technical expert evidence.


While Mellor J accepted the possibility that most entitlement disputes could and should be decided without any expert evidence, he concluded that the evidence required must depend on what issues arose in any particular case.

In the circumstances of this case, Mellor J found it

highly likely that there will be technical disputes at trial and some may well only emerge in the course of Dr Hill’s answers in cross-examination”.

Therefore, because technical disputes are to be addressed by expert evidence and not scientific advisors, the issues arising in this particular case necessitated an order for expert evidence.


This brief but useful decision provides clarity regarding the different roles of technical experts and scientific advisers in English patent actions (whether relating to issues of validity, infringement, entitlement or otherwise).

Specifically, where there are, or may be, disputed technical issues, technical experts will be required. Scientific advisers are appropriate where there are no disputed technical issues or, if helpful in a specific case, to supplement technical experts.

This is for general information only and does not constitute legal advice. Should you require advice on this or any other topic then please contact or your usual HLK advisor.

HLK bubble graphic HLK bubble graphic

Keep up-to-date with the latest IP insights and updates as well as upcoming webinars and seminars via HLK’s social media.