diff --git a/dandischema/metadata.py b/dandischema/metadata.py
index 21999ea..4c81325 100644
--- a/dandischema/metadata.py
+++ b/dandischema/metadata.py
@@ -21,6 +21,7 @@
 from .utils import (
     TransitionalGenerateJsonSchema,
     _ensure_newline,
+    sanitize_value,
     strip_top_level_optional,
     version2tuple,
 )
@@ -310,7 +311,7 @@ def migrate(
 def _get_samples(value: dict, stats: _stats_type, hierarchy: Any) -> _stats_type:
     if "sampleType" in value:
         sampletype = value["sampleType"]["name"]
-        obj = value["identifier"].replace("_", "-")
+        obj = sanitize_value(value["identifier"])
         if obj not in stats[sampletype]:
             stats[sampletype].append(obj)
     if "wasDerivedFrom" in value:
@@ -354,7 +355,7 @@ def _add_asset_to_stats(assetmeta: Dict[str, Any], stats: _stats_type) -> None:
                 if value["species"] not in stats["species"]:
                     stats["species"].append(value["species"])
             if value.get("identifier", None):
-                subject = value["identifier"].replace("_", "-")
+                subject = sanitize_value(value["identifier"])
                 if subject not in stats["subjects"]:
                     stats["subjects"].append(subject)
 
diff --git a/dandischema/tests/test_utils.py b/dandischema/tests/test_utils.py
index 75a62d4..71d9e7a 100644
--- a/dandischema/tests/test_utils.py
+++ b/dandischema/tests/test_utils.py
@@ -2,7 +2,13 @@
 
 import pytest
 
-from ..utils import _ensure_newline, name2title, strip_top_level_optional, version2tuple
+from ..utils import (
+    _ensure_newline,
+    name2title,
+    sanitize_value,
+    strip_top_level_optional,
+    version2tuple,
+)
 
 
 @pytest.mark.parametrize(
@@ -72,3 +78,13 @@ def test_newline() -> None:
 )
 def test_strip_top_level_optional(input_: type, expected_output: type) -> None:
     assert strip_top_level_optional(input_) == expected_output
+
+
+def test_sanitize_value() -> None:
+    # . is not sanitized in extension but elsewhere
+    assert sanitize_value("_.ext", "extension") == "-.ext"
+    assert sanitize_value("_.ext", "unrelated") == "--ext"
+    assert sanitize_value("_.ext") == "--ext"
+    assert sanitize_value("A;B") == "A-B"
+    assert sanitize_value("A\\/B") == "A--B"
+    assert sanitize_value("A\"'B") == "A--B"
diff --git a/dandischema/utils.py b/dandischema/utils.py
index c73167c..f82fac4 100644
--- a/dandischema/utils.py
+++ b/dandischema/utils.py
@@ -114,3 +114,25 @@ def strip_top_level_optional(type_: Any) -> Any:
     else:
         # `type_` is not an Optional
         return type_
+
+
+def sanitize_value(value: str, field: str = "non-extension", sub: str = "-") -> str:
+    """Replace all "non-compliant" characters with -
+
+    Of particular importance is _ which we use, as in BIDS, to separate
+    _key-value entries.  It is not sanitizing to BIDS level of clarity though.
+    In BIDS only alphanumerics are allowed, and here we only replace some known
+    to be offending symbols with `sub`.
+
+    When `field` is not "extension", we also replace ".".
+
+    Based on dandi.organize._sanitize_value.
+
+    .. versionchanged:: 0.8.3
+
+            ``sanitize_value`` added
+    """
+    value = re.sub(r"[_*\\/<>:|\"'?%@;,\s]", sub, value)
+    if field != "extension":
+        value = value.replace(".", sub)
+    return value