Gelatin Methacrylate/LAP

Figure 1: Live/dead image of human neonatal dermal fibroblasts encapsulated in bioprinted Gelatin Methacrylate

Figure 1: Live/dead image of human neonatal dermal fibroblasts encapsulated in bioprinted Gelatin Methacrylate


Gelatin Methacrylate is a gelatin-based hydrogel that reacts and crosslinks in the presence of LAP and Allevi blue light technology( 1,2). The recommended preparation provided in the user instruction below yields a streamlined matrix bioink that supports 3D printed cell-laden constructs. However, preparation can be modified by users to suit their needs.

Storage and Handling

GelMA should be stored at -20 °C. LAP should be stored away from light in a dry environment.

You Will Need

  • Metal or UV-block needles

  • Petri dish or well plate for printing

  • Sterile filters

  • Optional: Treated glass (See protocol)

  • Note: You can purchase GelMA and LAP with needles, filters and syringes included here.

Instructions for Use

  1. Measure 0.5% w/v LAP concentration and mix in cell media or PBS at 60°C. Mix until all LAP is dissolved.

  2. Measure 10% w/v GelMA concentration and add to solution from step 1. Mix at 60°C until all GelMA is dissolved.

  3. Heat solution from step 2 to 60°C and filter with a 0.45 µm syringe filter under sterile conditions.*

  4. Cool solution to 37°C, then mix in desired cell concentration in a sterile container. *

  5. Load cell-laden bioink into a 10 ml sterile luer lok syringe at 37°C. Cool on ice until bioink reaches room temperature, about 8 min.

    1. (**Critical step: GelMA can take a while to cool to room temperature. It is important to cool the material on ice prior to loading to speed up this process.)

  6. Load syringe into Allevi printer.

  7. Using the Allevi Bioprint Software, select your desired file, and prepare the print parameters.

* For prints without cells, steps 3 and 4 may be skipped.

Print Settings

*Critical step: Your needle can have significant effects on print settings. Be sure to use the suggested needle type or re-characteriz print parameters.
Speed (mm/s) Layer Height (mm) Nozzle Diam (mm) Gauge Pressure (psi) Print Temp (C)
4 0.3 0.3 27 Tapered 10-12 25
Crosslinking Parameters for printing with suggested GelMA and LAP concentrations.
Crosslinking During Print Post-Print Crosslinking
Layers Intensity (mW/cm^2) Time (s) Intensity (mW/cm^2) Time (s)
2 10 10 10 120


  1. Issues printing? Check out our Troubleshooting Guide.

  2. Gelation time and gel stiffness can be adjusted by varying the concentration of GelMA or LAP. For help adjusting print parameters please contact [email protected]

  3. A fill volume change of more than 2 ml may affect pressure settings.

  4. A lower gauge size or tapered gauge will require lower pressure, while a higher gauge will require higher pressure for extrusion. Lowering the gauge size will also generally lower resolution

Further Information

for further questions or information about these products, please contact [email protected]


[1] D. B. Kolesky et al, “3D Bioprinting of Vascularized, Heterogeneous Cell-laden Tissue Constructs,” Adv. Mater., vol. 26, pp. 3124-3130, 2014.

[2] B. D. Fairbanks et. al, “Photoinitiated Polymerization of PEG-diacrylate with lithium phenyl-2,4,6-trimethylbenzoylphosphinate: polymerization rate and cytocompatibility,” Biomaterials, vol. 30, no. 35, pp. 6702-6707, Dec 2009.