Collagenase Type IV is an endopeptidic matrix metalloproteinase MMP-18 derived from the bacterium Clostridium histolyticum that primarily degrades collagen type IV and VII and is commonly used to break down basement membranes (e.g., neural tissue, renal tissue) because of its mild activity.

Collagenase Type IV (0.5–2.5 g/mL) is primarily used in in vitro cell experiments to isolate pancreatic islet cells from pancreatic tissue[1]. Additionally, it can degrade type IV collagen in the basement membrane, promoting the invasion and metastasis of tumor cells[2].
Instructions for Use
1. Storage Solution Preparation
(1) Add 100 µL of HBSS containing Ca²⁺ and Mg²⁺ to each tube containing 100 mg of collagenase, gently vortex to dissolve, preparing a 1 g/mL (1000×) storage solution.
(2) Filter sterilize using a low protein-binding 0.22 µm filter membrane, aliquot into smaller portions, and store at -20°C in the dark.
2. Tissue Dissection
(1) Cut the tissue into 3-4 mm sized pieces and wash them several times with HBSS containing Ca²⁺ and Mg²⁺.
(2) Add sufficient HBSS containing Ca²⁺ and Mg²⁺ to fully immerse the tissue blocks, and add collagenase to achieve the required working concentration.
(3) Incubate at 37°C for 4-18 hours, using a horizontal shaker during digestion, and add 3 mM of CaCl₂ to enhance digestion efficiency.
(4) After the cells have dispersed, use a stainless steel or nylon mesh filter to collect the dispersed cells for further use.
3. Organ Perfusion
(1) Add collagenase to pre-warmed HBSS containing Ca²⁺ and Mg²⁺ at 37°C, and additionally add 3 mM of CaCl₂ to enhance separation efficiency.
(2) Perfuse the corresponding organ with collagenase working solution at the optimized rate.
(3) Filter the recovered perfusate through a stainless steel or nylon mesh filter to separate the dissociated cells or small tissue fragments from larger clumps.
(4) Wash the collected cells several times with HBSS without collagenase.
(5) Resuspend the cells in cell culture medium and calculate the viable cell density using an automated cell counter or other Methods.

In a mouse tumor model, local injection of Collagenase Type IV (at a dose of 10-50mg/kg) can degrade type IV collagen in the tumor stroma, significantly increasing drug penetration and reducing tumor volume. When combined with chemotherapy drugs, it significantly enhances the therapeutic effect. Furthermore, pre-treating the tumor tissue with a local injection of Collagenase Type IV at a dose of 10mg/kg prior to gene electroporation can significantly improve gene vector transfection efficiency, thereby enhancing the effectiveness of gene therapy[3].