The expiry date of the tubes for HbNO assessment shipped to you last month might be exceeded (like this one on the picture). The expiry date of these tubes is unusually closed due to the stability of the airtightness (vacuum inside). When we order them, the product has a shelf life of max. 6 months.
So, if you notice that your tubes are expired prior to use, please send me an email mentioning how many tubes you need and I'll send them to you.