The best type of sample to send to a diagnostic clinic is:

The best type of sample to send to a diagnostic clinic is:

• A. The smallest leaf possible, to save on shopping costs
• B. Plant tissue that has been dead for a long time
• C. Plant tissue from the transitional area between healthy and damaged areas
• D. Dry plant material

Answer: (C)

The most informative sample is tissue from the boundary between healthy and damaged areas. This transition zone shows the active edge of the problem, where the disease process is progressing and the plant is actively responding. By including both healthy and diseased tissue in one specimen, the diagnostician can compare what’s gone wrong and often detect the pathogen or the plant’s response signals more reliably. Fresh, living tissue at this edge is more likely to yield useful results than tissue that’s dead, desiccated, or entirely healthy, which may not reveal the current issue. A sample from the border is thus the best chance for an accurate diagnosis.

The most informative sample is tissue from the boundary between healthy and damaged areas. This transition zone shows the active edge of the problem, where the disease process is progressing and the plant is actively responding. By including both healthy and diseased tissue in one specimen, the diagnostician can compare what’s gone wrong and often detect the pathogen or the plant’s response signals more reliably. Fresh, living tissue at this edge is more likely to yield useful results than tissue that’s dead, desiccated, or entirely healthy, which may not reveal the current issue. A sample from the border is thus the best chance for an accurate diagnosis.