Possible Clues:

• TV-screen choice
• Al's map spoiled by some of the blood
• Highly ionized gas
• Emergency supply
• Type of modern TV
• Dad's getting left inside with Mum — it makes for a highly charged atmosphere
• Postscript covers American city close to mother offering blood supply
• Turns up after Dawn at society in Switzerland? It?s a concern for the bank!
• Blood-bank stock
• Type of flat-panel TV screen