Table 1.

Considerations for preclinical keloid studies

Contact institutional review board (IRB) to determine if patient consent is required for collection of keloid scar tissue. • Informed consent is required if protected health information (PHI) is collected or if patient can be identified by information collected. • An IRB protocol is necessary if you are required to obtain informed consent, even if discarded tissue is collected. • An IRB protocol may not be required if samples are de-identified, but check with your local IRB first to make sure.

Collect as much demographic and medical information on keloid patient as possible for every sample collected. • Patient age, race, sex, general health, and single/multiple scars • Scar etiology: cause, duration, and prior treatments • Family history

Confirm keloid diagnosis before initiating experiments. • View clinical photos • Examine histological sections

Carefully document scar characteristics. • Size, shape, thickness, pigmentation, ulceration, and infection • Locations of biopsies

Include normal controls in experiments and use “matched” controls whenever possible. • Ideally, nonlesional skin from keloid patient (although this may not be truly “normal” if patient predisposed to keloid formation). • For unrelated normal skin controls, try to match age, race, sex, and body site.

Always use multiple biological replicates. • “Biological” replicates are from different individuals; do not confuse with “technical” replicates.  ○ Biological replicates help control for person-to-person variability.  ○ Technical replicates help control for experiment-to-experiment variability. • Perform a power analysis to ensure sample size is large enough to detect a significant difference if one exists.

For mouse studies, select mouse strain(s) carefully. • Strain-specific differences may affect experimental outcomes. • Outbred mice may exhibit more mouse-to-mouse variability in phenotype compared with inbred mice.