A container system includes a flexible bag bounding a chamber. A probe port includes an elongated tubular member having an interior surface bounding a first passageway and extending between a first end and an opposing second end, the first passageway being closed at the first end and open at the second end; and a flange encircling and radially outwardly projecting from the tubular member at or toward the second end thereof, the flange being secured to the flexible bag so that the first end of the elongated tubular member projects into the chamber of the flexible bag while the open second end of the elongated tubular member is accessible from outside of the flexible bag. A probe is received within the first passageway of the probe port.