A method of making a set of labelled compounds by the use of a preferably particulate support, comprises dividing the support into lots, performing a different chemical reaction on each lot of the support, e. The detection circuit includes a tuned ratio circuit and an alternating current source AC-coupled to the tuned ratio circuit. A deformable element may be disposed between the shank and bit body. Anti-dropping levers prevent the tubular spool shaft from dropping from the first and second holder cores by pushing a shaft inner surface of the tubular spool shaft.