The Tasmanian Red Cross blood service wanting donors with O and A type of blood are at a low supply this time.

While stating that the plasma stock is down by two-thirds of the quantity needed the Australian Red Cross Blood Service is asking for donations this time.

Nick McGowan of the Red Cross said, "At the moment we're looking for people to donate blood, in particular platelets. Stocks have dropped over the Christmas and New Year period.”

Out of five litres blood in an adult about three litres is plasma. Plasma being a versatile product is used for treating immune deficiencies, burns and vaccines.

About 16 different products are made with plasma and these products are used to prevent and stop bleeding.

Seeing the developments taking place in medical sciences and rise in ageing population the blood service anticipates demand for plasma almost doubling in the next 10 years.

In Queensland alone the service is hoping to attract more than 26,000 donors each week.