Development of an Inquiry Laboratory Experiment for Upper Secondary School Biology – A Simple Preparation Method for Bacillus natto Cells from a Traditional Japanese Food “Natto” for Gram Staining and DNA Extraction – Tomoko KAGA 1* and Motoo ARAI 2 1 Biology Department, Osaka Prefectural Shiragiku Upper Secondary School, 1-1 Daisen-cho, Sakai, Osaka 590-0035, Japan; 2 Department of Applied Biological Chemistry, Graduate School of Agriculture and Biological Sciences, Osaka Prefecture University, 1-1 Gakuen-cho, Sakai, Osaka 599-8531, Japan (Received: 29 November 2002; Accepted: 21 August 2003)