A vial and system are configured to simplify fluid input and extraction therefrom. The vial has a first end opposite a second end and with a collapsible sidewall. The sidewall can be collapsed, such as by imparting a differential pressure between an interior and exterior of the vial, for simplified fluid extraction and smooth extraction without disturbing boundaries between separated components. The vial typically has a bulb at a first end and a neck extending away from the bulb and toward the second end. An inlet spaced from the first end can be configured to attach to various different interfaces or processing elements for input and output of fluids. A support cup can be provided for use with the vial during centrifugation to allow the vial to withstand any centrifugation forces. Various fluid processing methodologies are supported by the collapsible vial, especially including methods of separation of components of blood.