diff --git a/transcriptomics_data_service/db.py b/transcriptomics_data_service/db.py
index f60fbd1..0b12878 100644
--- a/transcriptomics_data_service/db.py
+++ b/transcriptomics_data_service/db.py
@@ -133,9 +133,7 @@ def _deserialize_gene_expression(self, rec: asyncpg.Record) -> GeneExpression:
     # CRUD: gene_expression_norm
     ############################
 
-    async def fetch_gene_expressions_by_experiment_id(
-        self, experiment_result_id: str
-    ) -> Tuple[GeneExpression, ...]:
+    async def fetch_gene_expressions_by_experiment_id(self, experiment_result_id: str) -> Tuple[GeneExpression, ...]:
         """
         Fetch gene expressions for a specific experiment_result_id.
         """
@@ -147,9 +145,7 @@ async def fetch_gene_expressions_by_experiment_id(
             res = await conn.fetch(query, experiment_result_id)
         return tuple([self._deserialize_gene_expression(record) for record in res])
 
-    async def update_normalized_expressions(
-        self, expressions: List[GeneExpression], method: str
-    ):
+    async def update_normalized_expressions(self, expressions: List[GeneExpression], method: str):
         """
         Update the normalized expressions in the database using batch updates.
         """
diff --git a/transcriptomics_data_service/main.py b/transcriptomics_data_service/main.py
index 4b58b7d..e76ccc0 100644
--- a/transcriptomics_data_service/main.py
+++ b/transcriptomics_data_service/main.py
@@ -46,4 +46,3 @@ async def lifespan(_app: FastAPI):
 app.include_router(ingest_router)
 app.include_router(experiment_router)
 app.include_router(normalization_router)
-
diff --git a/transcriptomics_data_service/routers/normalization.py b/transcriptomics_data_service/routers/normalization.py
index a92bcd8..d36729e 100644
--- a/transcriptomics_data_service/routers/normalization.py
+++ b/transcriptomics_data_service/routers/normalization.py
@@ -29,30 +29,29 @@ async def normalize(
     Normalize gene expressions using the specified method for a given experiment_result_id.
     """
     # method validation
-    if method not in ['tpm', 'tmm', 'getmm']:
+    if method not in ["tpm", "tmm", "getmm"]:
         raise HTTPException(
-            status_code=status.HTTP_400_BAD_REQUEST,
-            detail=f"Unsupported normalization method: {method}"
+            status_code=status.HTTP_400_BAD_REQUEST, detail=f"Unsupported normalization method: {method}"
         )
 
     # load gene lengths
-    if method in ['tpm', 'getmm']:
+    if method in ["tpm", "getmm"]:
         if gene_lengths_file is None:
             raise HTTPException(
                 status_code=status.HTTP_400_BAD_REQUEST,
-                detail=f"Gene lengths file is required for {method.upper()} normalization."
+                detail=f"Gene lengths file is required for {method.upper()} normalization.",
             )
         gene_lengths = await _load_gene_lengths(gene_lengths_file)
 
     raw_counts_df = await _fetch_raw_counts(db, experiment_result_id)
 
     # normalization
-    if method == 'tpm':
+    if method == "tpm":
         raw_counts_df, gene_lengths_series = _align_gene_lengths(raw_counts_df, gene_lengths)
         normalized_df = read_counts2tpm(raw_counts_df, gene_lengths_series)
-    elif method == 'tmm':
+    elif method == "tmm":
         normalized_df = tmm_normalization(raw_counts_df)
-    elif method == 'getmm':
+    elif method == "getmm":
         raw_counts_df, gene_lengths_series = _align_gene_lengths(raw_counts_df, gene_lengths)
         normalized_df = getmm_normalization(raw_counts_df, gene_lengths_series)
 
@@ -67,9 +66,9 @@ async def _load_gene_lengths(gene_lengths_file: UploadFile) -> pd.Series:
     Load gene lengths from the uploaded file.
     """
     content = await gene_lengths_file.read()
-    gene_lengths_df = pd.read_csv(StringIO(content.decode('utf-8')), index_col='GeneID')
-    gene_lengths_series = gene_lengths_df['GeneLength']
-    gene_lengths_series = gene_lengths_series.apply(pd.to_numeric, errors='raise')
+    gene_lengths_df = pd.read_csv(StringIO(content.decode("utf-8")), index_col="GeneID")
+    gene_lengths_series = gene_lengths_df["GeneLength"]
+    gene_lengths_series = gene_lengths_series.apply(pd.to_numeric, errors="raise")
     return gene_lengths_series
 
 
@@ -84,15 +83,11 @@ async def _fetch_raw_counts(db, experiment_result_id: str) -> pd.DataFrame:
 
     data = []
     for expr in expressions:
-        data.append({
-            'GeneID': expr.gene_code,
-            'SampleID': expr.sample_id,
-            'RawCount': expr.raw_count
-        })
+        data.append({"GeneID": expr.gene_code, "SampleID": expr.sample_id, "RawCount": expr.raw_count})
     df = pd.DataFrame(data)
-    raw_counts_df = df.pivot(index='GeneID', columns='SampleID', values='RawCount')
+    raw_counts_df = df.pivot(index="GeneID", columns="SampleID", values="RawCount")
 
-    raw_counts_df = raw_counts_df.apply(pd.to_numeric, errors='raise')
+    raw_counts_df = raw_counts_df.apply(pd.to_numeric, errors="raise")
 
     return raw_counts_df
 
@@ -103,7 +98,9 @@ def _align_gene_lengths(raw_counts_df: pd.DataFrame, gene_lengths: pd.Series):
     """
     common_genes = raw_counts_df.index.intersection(gene_lengths.index)
     if common_genes.empty:
-        raise HTTPException(status_code=status.HTTP_400_BAD_REQUEST, detail="No common genes between counts and gene lengths.")
+        raise HTTPException(
+            status_code=status.HTTP_400_BAD_REQUEST, detail="No common genes between counts and gene lengths."
+        )
     raw_counts_df = raw_counts_df.loc[common_genes]
     gene_lengths_series = gene_lengths.loc[common_genes]
     return raw_counts_df, gene_lengths_series
@@ -115,24 +112,22 @@ async def _update_normalized_values(db, normalized_df: pd.DataFrame, experiment_
     """
     # Fetch existing expressions to get raw_count values
     existing_expressions = await db.fetch_gene_expressions_by_experiment_id(experiment_result_id)
-    raw_count_dict = {
-        (expr.gene_code, expr.sample_id): expr.raw_count for expr in existing_expressions
-    }
+    raw_count_dict = {(expr.gene_code, expr.sample_id): expr.raw_count for expr in existing_expressions}
 
     normalized_df = normalized_df.reset_index().melt(
-        id_vars='GeneID', var_name='SampleID', value_name='NormalizedValue'
+        id_vars="GeneID", var_name="SampleID", value_name="NormalizedValue"
     )
 
     expressions = []
     for _, row in normalized_df.iterrows():
-        gene_code = row['GeneID']
-        sample_id = row['SampleID']
+        gene_code = row["GeneID"]
+        sample_id = row["SampleID"]
         raw_count = raw_count_dict.get((gene_code, sample_id))
 
         if raw_count is None:
             raise HTTPException(
                 status_code=status.HTTP_404_NOT_FOUND,
-                detail=f"Raw count not found for gene {gene_code}, sample {sample_id}"
+                detail=f"Raw count not found for gene {gene_code}, sample {sample_id}",
             )
 
         gene_expression = GeneExpression(
@@ -140,9 +135,9 @@ async def _update_normalized_values(db, normalized_df: pd.DataFrame, experiment_
             sample_id=sample_id,
             experiment_result_id=experiment_result_id,
             raw_count=raw_count,
-            tpm_count=row['NormalizedValue'] if method == 'tpm' else None,
-            tmm_count=row['NormalizedValue'] if method == 'tmm' else None,
-            getmm_count=row['NormalizedValue'] if method == 'getmm' else None,
+            tpm_count=row["NormalizedValue"] if method == "tpm" else None,
+            tmm_count=row["NormalizedValue"] if method == "tmm" else None,
+            getmm_count=row["NormalizedValue"] if method == "getmm" else None,
         )
         expressions.append(gene_expression)
 
diff --git a/transcriptomics_data_service/scripts/normalize.py b/transcriptomics_data_service/scripts/normalize.py
index cca47bc..a1135ca 100644
--- a/transcriptomics_data_service/scripts/normalize.py
+++ b/transcriptomics_data_service/scripts/normalize.py
@@ -1,5 +1,6 @@
 import pandas as pd
 
+
 def read_counts2tpm(counts_df, gene_lengths, scale_library=1e6, scale_length=1e3):
     """
     Convert raw read counts to TPM (Transcripts Per Million).