Human fibroblast cultures — these are best classified as which type of cell line with finite lifespan and stable characteristics?

Introduction / Context:
Human dermal fibroblasts are a classic model for primary, finite cell culture. They divide for a limited number of passages before senescence. Distinguishing finite primary cultures from established (immortal) lines is important for experimental design and interpretation.

Given Data / Assumptions:

• Example given: human fibroblast.
• Typical behavior: finite doubling potential (Hayflick limit) and contact inhibition.
• No evidence of transformation or immortalization stated.

Concept / Approach:

Primary fibroblasts are finite, genetically stable compared to transformed lines, and maintain many physiological characteristics. They are not “established” (immortal) unless specifically transformed or telomerase-extended. They are not malignant and are distinct from pluripotent stem cell lines.

Step-by-Step Solution:

Verification / Alternative check:

Standard cell culture references classify human fibroblasts as finite primary or “normal diploid” cell lines with predictable senescence.

Why Other Options Are Wrong:

Established lines are immortal; “cell transformations” implies oncogenic change; iPSC lines are reprogrammed pluripotent and behave differently.

Common Pitfalls:

Assuming “stable” means immortal; in cell culture, “finite lifespan” and genetic stability characterize primary fibroblasts.

Final Answer:

Stable primary cell lines (finite lifespan)