Update app.py

app.py

@@ -64,7 +64,7 @@ def read_dna_sequence(dna_text, fasta_file):
         dna_sequence = dna_sequence.upper()
         warning += "\n⚠️ Note: DNA sequence was converted to uppercase (lowercase nucleotides are not supported)."
 
-    if error != "":
+    if error == "":
         # If there was an error before, no need to check the content of the sequence. Otherwise, check that only ACGTN are used
         for nucleotide in dna_sequence:
             if nucleotide not in ["A", "C", "G", "T", "N"]:
@@ -217,6 +217,8 @@ You can either paste a sequence or upload a FASTA file.
 ### Limitations and Disclaimer
 ChatNT can only handle questions related to the 27 tasks it has been trained on, including the same format of DNA sequences. ChatNT is not a clinical or diagnostic tool. It can produce incorrect or “hallucinated” answers, particularly on out‑of‑distribution inputs, and its numeric predictions may suffer digit‑level errors. Confidence estimates require post‑hoc calibration. Users should always validate critical outputs against experiments or specialized bioinformatics pipelines.
 
+---
+
 ### How to query the model ?
 ChatNT works like an advanced assistant for analyzing DNA sequences — but it has some important rules.
 
@@ -234,6 +236,9 @@ Examples of bad queries:
 - "Replace the all 'A' nucleotides by 'G' in this sequence `<DNA>`".
 
 For more examples, you can refer to the [training dataset](https://huggingface.co/datasets/InstaDeepAI/ChatNT_training_data).
+
+---
+
                 """
             )
         with gr.Column(scale=1):