Both form native fibrillar gels, but they differ in gelation kinetics and final mechanical properties. Rat tail collagen generally gels faster and produces a slightly stiffer matrix, and is the more commonly cited option in migration and invasion literature. Bovine collagen gels more slowly, which can help when a longer working time is needed to distribute cells. Where a published protocol specifies a source, match it.

Pepsin treatment removes the telopeptide regions at the ends of the collagen molecule. Those regions drive natural cross-linking and fibril assembly, so pepsinized collagen forms a less physiological network. ibidi Collagen Type I is non-pepsinized, which means the resulting gel architecture more closely resembles native extracellular matrix.

The 10 mg/ml stock lets you reach higher final collagen concentrations, and therefore stiffer gels, without diluting your cell suspension excessively. If you are working at standard final concentrations of roughly 1 to 2 mg/ml, the 5 mg/ml stock is usually sufficient and easier to pipette accurately.

Yes. Diluted to a coating concentration and applied to the growth surface, it provides a collagen I substrate for improved adhesion of primary cells and other adhesion-dependent lines. This works on ibidi Untreated and ibiTreat surfaces alike, though coating is most often used on the hydrophobic Untreated surface.

Store at 2 to 8 degrees Celsius and keep the solution cold while pipetting, since collagen begins polymerising as it warms toward neutral pH and room temperature. Prepare neutralised gel mixes on ice, work quickly, and avoid introducing air bubbles, which become optical artefacts once the gel sets.