Gelatin Methacrylate/LAP

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Gelma_d14_01_10X_Zcrop_Max_Rotate_Straight (1)

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 BioBots 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 (we suggest these)
  •  Petri dish or well plate for printing
  •  Sterile filters (we suggest these)
  •  Optional: Treated glass (See protocol)

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 90°C and filter with a 0.2 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.

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.

  1.  Load syringe into BioBots printer.
  2.  Prepare your design file through Repetier Host, then upload the sliced gcode file to biobots software.

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

Print Settings

Slic3r Settings
Speed (mm/s) Layer height (mm) Nozzle Diam (mm)   Gauge


0.3 0.3 27 Tapered

*Critical step: Your needle can have significant effects on print settings. Be sure to use the suggested needle type or re-calibrate print parameters.

Print Pressure and Temperature Settings
Pressure (psi) Print Temp (°C)


Print Crosslink Settings


 Intensity Time (sec)


15% 10
Post Print Crosslink Settings


Time (sec)




  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
  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


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