The ELISA and ImmunoStrip are reliable tools for Acidovorax avenae subsp. citrulli (Aac), the causal agent of bacterial fruit blotch in watermelon, squash, pumpkins, and cantaloupe. The test can be used with leaves, fruit, bacterial cultures, and seedlings exhibiting symptoms of Aac. This test was designed to produce a low background signal with necrotic seedlings.