Fly fishing in a river. Fly fishing is an angling method in which an artificial 'fly' is used to catch fish. The fly is cast using a fly rod, reel, and specialized weighted line. Casting a nearly weightless fly or 'lure' requires casting techniques significantly different from other forms of casting.
Antistreptolysin O (ASO) titer is a blood test to measure antibodies against streptolysin O, a substance produced by Group A Streptococcus bacteria. ASO titer; ASLO. Blood is typically drawn from a vein, usually from the inside of the elbow or the back of the hand.
A negative ASO or ASO that is present at very low titers means the person tested most likely has not had a recent strep infection. This is especially true if a sample taken 10 to 14 days later is also negative (low titer of antibody) and if an anti-DNase B test is also negative (low titer of antibody).