The phrase "an indispensable issue" is correct and usable in written English.
It can be used when referring to a topic or matter that is essential or crucial in a particular context.
Example: "Addressing climate change is an indispensable issue that requires immediate attention from policymakers."
Alternatives: "a critical matter" or "an essential topic".
To the established model for describing production of the antibody-forming cells, we were able to append an indispensable issue in considering the maturation of humoral immune response.
Observation of the chemical properties, such as the composition, distribution, structure, species, and surface reactions of solid materials, has been an indispensable issue in various fields of science and engineering, such as materials chemistry, environmental geochemistry, photochemistry, catalysis, or chemical synthesis.
Finally, an indispensable issue in the origin of the proto-translation system is how the specificity between amino acids and their cognate adaptors could have been established, which is associated with the origin of the genetic code (see below).
Effectual data size and degree of significance are also indispensable issues to be evaluated.
The Special Issue represents an indispensable resource for academics, policy-makers and practitioners with interests in recycling and packaging waste management.
Two Sundays before Make Music New York, the Brooklyn-based venue Issue Project Room, an indispensable site of offbeat programming, organized its own sonic jamboree.
There are however some issues nowadays considered an indispensable part of high-quality developed clinical practice guidelines, which most of the Latin American guidelines have not included: patients' views and preferences, procedures for updating the guidelines, and disclosure of conflicts of interest of guideline development members.
Especially, humidity is an indispensable factor when an experimental investigation on the issue of stability is conducted.
Tatler runs 10 annual "special issues" which no doubt form an indispensable guide for newly arrived Russians.
Nevertheless, media plays an indispensable role in shedding light on human rights issues that far too often affect many African countries.
To clarify many of the issues raised above there is an indispensable need to re-evaluate the selective mitophagy pathway in post-mitotic neurons expressing the endogenous wildtype or mutant parkin and PINK1 proteins.
