There�s stem cell donation and bone marrow donation.
Stem cell donation – a lot more common, similar to donating blood, but takes longer.
Bone marrow donation – typically done when a child is the recipient, much less common, and it�s a procedure with anesthesia.
Gift of life does both, and they will tell you which one is necessary for the patient.
I have a friend that donated stem cells. One either donate at a hospital nearby, or if you�d like Gift of Life will fly you to Florida, to donate at their HQs.
People with similar ancestry tend to match, so a Jew matching with a Jew is quite likely.
It�s truly an opportunity to save a life, this is literally a cure for the patient and it�s possible that they will die without it.