Rat Primary Aortic Fibroblasts from AcceGen Biotech are isolated from tissue of neonatal Sprague-Dawley Rats. Rat Primary Aortic Fibroblasts are grown in T75 tissue culture flasks pre-coated with gelatin-based solution for 0.5 hour and incubated in AcceGen Biotech's Cell Culture Medium for 3-7 days. Cultures are then expanded. Prior to shipping, cells are detached from flasks and immediately cryo-preserved in vials. Each vial contains at least 1x10^6 cells per ml and is delivered frozen.Cells are negative for bacteria, yeast, fungi, and mycoplasma. Rat Primary Aortic Fibroblasts are tested for expression of marker using the antibody of anti-FSP1/S100A4 by immunofluorescence staining and can be expanded by 2-4 passages at a split ratio of 1:2 under the cell culture conditions specified by AcceGen Biotech. Repeated freezing and thawing of cells is not recommended.Standard biochemical procedures performed with fibroblast cultures include the assays of cell to cell interaction, PCR, Western blotting, immunoprecipitation, immunofluorescent staining, immunofluorescent flow cytometry or generating cell derivatives for desired research applications.