The disclosure provides a system and method to safely and efficiently store and transport process tubes in a carrier tray comprising prior to and during amplification of nucleotides in the process tubes. The process tube disclosed includes a securement region having an annular ledge, a neck, and a protrusion. The securement region of the process tube can secure the process tube in a port of the carrier tray, but still allows the process tube to adjust or float in order to align the process tube into a rigid heater well of a thermal cycler.