Hi Henson Yang, for the colon organoids, besides EGF, R-Spondin and Noggin, Wnt3a should be added to the medium.

For the lyophilized growth factors stored at -20°C or -80°C you should follow the expiration date given on the tube.

For the growth factors that were reconstituted ~ 1 year ago:

1) if a carrier protein (such as BSA) was used for the reconstitution,

2) if freeze-thaw cycles were avoided (the best are single-use aliquots) and

3) if aliquots were properly stored (-20°C or -80°C),

then the growth factors should still work, however their biological function might be reduced.

Hello

i agree with Agnieszka Pastula , this a good answer .

Good Luck