Methods and materials for the detection of melamine in test samples such as foodstuffs are described. The locking pin is moveable in a first direction, which urges a tapered end of the locking pin to engage a tapered recess in the rotor, and a second direction, opposite the first direction, to disengage the rotor. For example different combination may be used depending on the type of content being requested. The device may also base determination of a signal blocking occurrence on input from a status detection module. Column memories may be provided to hold the input matrix data, so that each row may be read by simultaneously accessing the same index in each column memory. The present invention particularly relates to the soybean variety APA94-31572 and its progeny, and methods of making APA94-31572.