Repository Facility: The Milano Cord Blood Bank

Abstract

In spite of abundant literature on cryobiology, relatively limited published information is available on specific features of the facilities where biological materials are stored. In this article the repository facility of a large cord blood bank is described. The 122 sq m biostorage area, which is part of the 226 sq m Milano Cord Blood Bank, is located in the basement of a hospital blood transfusion service. The repository area was designed to contain 35 liquid nitrogen (LN) tanks equipped with an automated refilling system. It was constructed according to Italian and French norms and guidelines. The current setting includes the following elements: an outdoor 6000 L reservoir connected to the area through a LN vacuum line, 30 LN tanks, a ventilation system interfaced to six oxygen sensors and a management system based on a programmable logic controller (PLC) linked to commercial proprietary software for continuous and real time monitoring of LN tanks and of the safety parameters of the repository area. The PLC manages local and remote alarms, the activation of devices in the area, and the ventilation system. The containers are monitored for temperature and LN level. The latter is set between 60 and 80% to ensure a temperature lower than –135°C, with a prealarm setpoint at –145°C. The LN refilling of the containers is fully automated, with the possibility of manual adjustments. The ventilation system switches from 10 to 25 volumes/hour during container refilling or when oxygen percentage in the room falls below 19%. Staff safety is ensured by audio and visual alarms placed both inside and outside the area and by a formal training course. Outside regular daily working hours (Mon to Fri, 8:00 to 20:00), an operator switches automatic alarm calls to a maintenance company. Access to the area is regulated according to levels of authorization. The features of the repository ensure both operator safety (through continuous control of oxygen levels) and product quality (through real time monitoring of tanks and LN distribution). The area passed a formal inspection during the process of accreditation of the Milano Cord Blood Bank by the Foundation for the Accreditation of Cellular Therapy, which was acquired on December 14^th, 2004.