Experts don’t agree about this, but when in doubt, it is safer to utilize the serial comma. (“red, white, and blue” instead of “red, white and blue”). One of the reasons that it is safer to use this comma is to ensure clarity, especially in specialized or legal writing. There was a courtroom case where there is disagreement as to the way the money ought to be divided among 3 people due to having less the serial comma. (The can stated that “Bob, Betty and Jane” had been to split the money. Because of the lacking serial comma, there was confusion concerning whether Bob got 50% and Betty & Jane split the various other 50%, or whether each person got 1/3.) So to be safe, always utilize it.