Reagent mixtures and testing procedures for detecting the presence or absence of various target substances such as aureus; vancomycin-resistant enterrococcus; Group B Streptococcus; E. Each individual element has an axial twist direction in an opposite direction from the axial twist direction of the collective multi-element assembly. Training symbols are inputted to the control unit. When the operator stands and the seat cushion rebounds, air is provided to the seat from the chamber.