Innovative screening of novel bioengineered cotton fibers containing oligochitin

The aim of this paper is to establish a test method for the screening of bioengineered cotton fibers with an improved reactivity through the incorporation of positively charged nitrogen moieties. For this purpose a spectrophotometric method based on the absorption of a negatively charged dye (Acid Orange 7) is extensively studied. The processing parameters have been optimized for analyzing small amounts of fibers and the feasibility of the method is examined by using two other well established techniques for nitrogen analysis. Good correlations were obtained between the different methods, however, the reproducibility of the Acid Orange 7 was superior to the other two methods. Moreover, statistically significant differences were found between fibers from cotton lines designed to produce oligochitin and control fibers without oligochitin. This shows that the proposed method is capable of accurately detecting increased nitrogen levels in bioengineered cotton fibers.