Fibroblast morphology and marker expression remain consistent during prolonged culture.

<p>Fibroblast lines were immunostained with antibodies FSP1 and TE7 at multiple consecutive passages (A). Passage numbers are indicated above the panels. Morphology, FSP1 and TE7 staining did not change during five consecutive subculturings (n = 6, representative images from line NM34737, carrying the PSEN1 M146I mutation are shown). FSP1 levels were also detected by western blotting of fibroblast cell lysates (B). FSP1 was detected as a single band at 12 kDa in all fibroblast lines examined (top panel, n = 6). β-actin was used as a loading control (bottom panel). No variation in FSP1 levels was observed between passages or between cell lines.