FAQ

Some 28 types of collagen types have been identified. Each type of collagen has a different role, and for example, type I collagen, which is most abundant in the body, forms fibrous structures in tissues such as skin and bones, playing roles in providing a scaffold for cells and maintaining mechanical strength.

Collagen is a protein composed of three polypeptide chains that form a triple-helix structure. When collagen is hydrolyzed under heat, the triple-helix unwinds and the secondary structure is partially lost. This process is referred to as the denaturation of collagen – gelatin is simply denatured collagen. Collagen dissolves in acidic solutions but has a tendency to be insoluble in neutral conditions.

Fibrous collagens, such as type I collagen, can remain dissolved in neutral solutions containing physiological concentrations of salt at low temperatures. However, when heated, the molecules aggregate and form a fibrous structure, creating a gel that retains moisture.

Collagen for research use (liquid form) is shipped in a frozen state. The collagen solution remains stable for long periods when frozen. When using, please thaw it in a refrigerator. After thawing, avoid repeated freeze-thaw cycles and store it in the refrigerator.

Collagen dissolves in acidic solutions. When using it for cell culture, it is recommended to dissolve it in 5 mM acetic acid or 1 mM hydrochloric acid, as stronger acids can make neutralization difficult. Additionally, since this product is not sterile, it should be filtered through a 0.45 μm filter before use in cell culture. The collagen concentration can be selected as desired, but if the concentration exceeds 5 mg/mL, the viscosity increases, making handling more difficult. When preparing a high concentration, it is easier to dissolve uniformly by first dispersing it in an aqueous solution and then adjusting the acidity.

After dissolution, like the collagen for research use (liquid form), please avoid freeze-thaw cycles as much as possible and store it in the refrigerator.

Collagen in biological tissues forms cross-links between molecules, with the majority being insoluble, but a small amount can dissolve in acidic solvents. Acid-extracted collagen (ASC) is a purified form of this slightly dissolved collagen, retaining a structure close to that in vivo. On the other hand, pepsin-solubilized collagen (PSC) is purified from collagen that has been dissolved by pepsin, which cleaves the cross-linked regions (telopeptide regions). Therefore, there is a difference in the presence of telopeptide regions between ASC and PSC, and the properties of the gels formed under physiological conditions also differ. In the case of Type I collagen, ASC can form clearer and stronger gels compared to PSC.

Even with the same type of collagen, the characteristics vary depending on the animal species. For example, type I collagen derived from bovine dermis forms a stronger gel compared to that derived from porcine dermis.

Collagen gels can be prepared by dissolving collagen in a neutral solution containing physiological concentrations of salt under low-temperature conditions, followed by heating (around 37°C) while keeping it undisturbed. The higher the collagen concentration, the stronger the gel will be, but the gelation time becomes shorter, making the handling more difficult. For a detailed protocol, please refer to the instructions for use.

We recommend using Nippi’s Brightase-C, tissue dissociation recombinant enzymes. For the method of cell harvesting and subculture using Brightase-C, please refer to the instructions for use.

The particle size of the powdered collagen is below 1 mm, and specific size control is not performed.

MediGelatin HMG-BP is alkali-treated with an average molecular weight (Mw) ranging from 60,000~300,000 Da. Nippi High-grade Gelatin AP is derived from acid-treated gelatin that has been hydrolized, with an average Mw of approximately 8,000 Da, which does not form a gel.

MediGelatin HMG-BP has high gel strength (over 250g), and Nippi High-grade Gelatin AP does not form a gel.

The gelatin without cross-linking process will be rapidly decomposed. Cross-linked gelatin can remain for more than one week, however, it is difficult that it can remain more than one month.

MediGelatin HMG-BP undergoes alkali treatment, which deamidates the amide groups on the amino acid side chains, shifting the isoelectric point from around 9 to around 5. As a result, it can form electrostatic bonds with basic substances, allowing for the controlled release of basic substances in the body as the gelatin is decomposed.

We can process Low Endotoxin Gelatin series into different forms including sponge or powder form. For more details, please contact us.

Bulk products are available. Please contact us.