In the bDNA test, a chemical reaction causes HIV RNA to release light. The amount of light is directly proportional to the amount of HIV RNA, so the light is measured for a result. At this time, no bDNA testing kits are approved by the FDA.

Sources:

• "Measuring the Virus." April 1995. AIDS Treatment Data Network. 10 Feb. 2004 <http://www.aegis.com/pubs/atdn/1995/ATR01805.html>.
• "Viral Load Tests." The Simple Facts Project . 2002. AIDS Treatment Data Network. 16 Jan. 2004. <http://www.aegis.com/factshts/network/simple/viral.html>.