To perform organoid plating, first, remove the supernatant from the centrifuge and washed hepatocellular carcinoma cells. Re-suspend the cells in the 50 microliters of basement membrane extract, or BME, per well, for plating. Next, suspend the cells in advanced DMEM/F12.
Then gently pipette the cell aggregates until an even suspension is seen. Add BME to the suspension, ensuring that the BME concentration is between 30 and 50%Now seed 50 microliters of BME droplets with cell clusters in the center of a 24 well plate. Allow the droplets to solidify at 37 degrees Celsius for 20 minutes.
Add 500 microliters of prewarmed medium to each well and incubate in a cell incubator at 37 degrees Celsius. Refresh the culture medium every two to three days. After two weeks, replace the isolation medium with the organoid expansion medium.
After seven to 10 days of culturing, once the organoids have reached the appropriate density, process the cultures as needed. To passage the organoids, first preheat ultra low attachment surface cell culture plates in an incubator. Next, thaw the frozen BME overnight at four degrees Celsius until right before usage.
Prewarm the organoid harvest solution and trypsin substitute at 37 degrees Celsius for 30 minutes. Following the preparation stage, remove the culture medium from the organoid culture plate. Then transfer the organoid suspension into a 15 milliliter tube.
Now add organoid harvesting solution in proportion to the amount of BME. To mix the suspension, use a 1000 microliter pipette gun to scrape and pipette up and down. After incubating the tube at room temperature for 30 minutes, use a one milliliter pipette to carefully aspirate the BME.
Ensure that the BME is fully dissolved. Monitor the extract every 10 minutes until a clear organoid cell cluster is visible. Then centrifuge at room temperature at 400 g for five minutes.
Remove as much of the supernatant as feasible. To start enzymatic digestion of the hepatocellular carcinoma organoids, add one to five milliliters of the prewarmed trypsin substitute to the cultured organoid pellet. Incubate the suspension at 37 degrees Celsius for two minutes.
Use a microscope to verify if organoids dissociate into small clusters of two to 10 cells. To stop the digestion, add an appropriate volume of cold basal medium. Then centrifuge the organoids at 400 g for five minutes at eight degrees Celsius.
Carefully remove as much supernatant as possible. Re-suspend the desired number of organoids in the proper matrix for plating. Every 10 days passage the organoids, depending on the density of organoid growth.
HCC organoids spheroids were observed within three days of culture. Compact spheroids with rounded edges and permeable cytosol were seen on the initial day of establishment. Organoids were similarly sized and had the largest diameter when cultured in 30 to 50%BME.
The BME was most fragmented at 10%resulting in the smallest organoids. The BME was most intact at 100%but resulted in organoids with intermediate diameter. The proliferating HCC organoid attained a size exceeding 500 micrometers in each culture after three generations.
Substantially sized HCC organoids of higher than 1000 micrometers were obtained within a 20 day culture period.
