Triple test Triple test The triple test, also called triple screen, the Kettering test or the Bart's test, is an investigation performed during pregnancy in the second trimester to classify a patient as either high-risk or low-risk for chromosomal abnormalities (and neural tube defects). The term "multiple-marker screening test" is sometimes used instead. This term can encompass the "double test" and "quadruple test" (described below). The Triple screen measures serum levels of AFP, estriol, and beta-hCG, with a 70% sensitivity and 5% false-positive rate. It is complemented in some regions of the United States, as the "Quad screen" (adding inhibin A to
Quadruple reed to play". Presumably a quadruple reed is folded twice, in opposite directions, instead of once (\/\ or \/\/ instead of \/ shaped), or either folded twice in the same direction or wrapped around (◎ instead of ○ shaped). Both options could result in what may be considered a doubly thick double reed. Quadruple reed A quadruple reed is a type of reed by means of which the sound is originated in various wind instruments. The term "quadruple reed" comes from the fact that there are four pieces of dried palm leaf vibrating against each other, in pairs. A quadruple reed,