Instructions for storage and transport of suspected or confirmed human and animal specimens and virus isolates of pandemic (H1N1) 2009

Publication details

Publication date: January 2013 (originally posted on 20 May 2009, revised on 12 June 2009, 16 July 2009, May 2010)

Specimen storage

Specimens in viral transport medium for viral isolation should be kept at 4 °C and transported to the laboratory promptly. If specimens are transported to the laboratory within 2 days, they may be kept at 4 °C; otherwise they should be frozen at or below –70 °C . Repeated freezing and thawing must be avoided to prevent loss of infectivity. Sera may be stored at 4 °C for approximately one week, but thereafter should be frozen at –20 °C.

Specimens should be collected and transported in a suitable transport medium, on ice or in liquid nitrogen. Specimens collected for influenza virus isolation should not be stored or shipped in dry ice (solid carbon dioxide) unless they are perfectly sealed in glass or sealed, taped and double plastic-bagged. Carbon dioxide can rapidly inactivate influenza viruses if it gains access to the specimens through imperfect seals: microscopic leaks in the seal may allow carbon dioxide gas to penetrate the primary container as a vacuum is created during freezing.

Specimen transport

The safe transport of virus cultures, isolates and patient specimens, in compliance with applicable national and/or international regulations for the transport of infectious substances, is described in Safe transport of pandemic influenza A (H1N1) 2009 virus cultures, isolates and patient specimens as Biological Substance, Category B (see the link below).

Guidance to assist shippers with classifying, documenting, marking, labelling and packaging infectious substances is available at A guide for shipping infectious substances (see the link below). Shippers are advised to follow this guidance when shipping infectious substances.

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