Strict hygiene rules keep tissue-processing cleanrooms free of contamination

Staff at a cleanroom complex at Tartu University Hospital follow strict hygiene procedures to prevent contamination while processing tissue for transplantation, ERR reported in its Ringvaade programme. Doctor Katre Maasalu, who leads the hospital’s skeletal tissue bank, said the tissues must be processed in exceptionally clean conditions to ensure they are safe to transplant.

Other hospitals have individual cleanrooms, Maasalu said, but not a complete cleanroom complex. She added that advances in cell science have made increasingly sophisticated processing possible.

Preparing for work takes time. Staff remove all jewellery, makeup and underwear, and wear garments that cover their entire bodies. The rooms are kept cool, said Tuuli Laeneste, an environmental specialist at the hospital’s cleanroom complex. Workers must avoid touching the outside of their work clothes, and are trained to put them on so that microbiological tests of the outer surface come back negative.

Maasalu said she must pass through three or four rooms to reach her workplace. She described the first as having the highest pressure and said pressure increases in each subsequent room, pushing contaminants out. Each room also has a boundary between dirtier and cleaner areas.

A traffic-light system on the ceiling indicates the rooms’ condition. Green means it is safe to work, Maasalu said. The system counts particles and bacteria that could contaminate the room, and staff must work calmly to avoid stirring up contaminants.

Maasalu also said staff must not wash or shower for at least two hours before work, because washing opens the pores and can increase the risk of contaminating the tissues.