diff --git a/zaaReloaded2/Importer/ZaaImporter/LaurisItem.cs b/zaaReloaded2/Importer/ZaaImporter/LaurisItem.cs
index 7d76f9e..2996795 100755
--- a/zaaReloaded2/Importer/ZaaImporter/LaurisItem.cs
+++ b/zaaReloaded2/Importer/ZaaImporter/LaurisItem.cs
@@ -103,19 +103,15 @@ namespace zaaReloaded2.Importer.ZaaImporter
             // "HBs-Antigen: neg. ;"
             // "Erythrozyten (U): + [negativ]"
             Match match;
-            Regex numericalRegex = new Regex(
-                @"(?<name>[^:]+):\s*(?<value>[\d,.]+)\s*(?<limits>\[[^\]]+])?\s*(?<unit>[^;]+)?");
-            Regex categoricalRegex = new Regex(
-                @"(?<name>[^:]+):\s*(?<value>[^[;]+)\s*(\[(?<normal>[^\]]+)])?");
-            if (numericalRegex.IsMatch(LaurisText))
+            if (_numericalRegex.IsMatch(LaurisText))
             {
-                match = numericalRegex.Match(LaurisText);
+                match = _numericalRegex.Match(LaurisText);
                 ParseLimits(match);
                 Value = match.Groups["value"].Value.Trim().Replace(',', '.');
             }
             else
             {
-                match = categoricalRegex.Match(LaurisText);
+                match = _categoricalRegex.Match(LaurisText);
                 Normal = match.Groups["normal"].Value.Trim();
                 Value = match.Groups["value"].Value.Trim();
             }
@@ -136,8 +132,7 @@ namespace zaaReloaded2.Importer.ZaaImporter
         {
             if (match.Groups["limits"].Success)
             {
-                Regex limitRegex = new Regex(@"\[(?<limit1>[-\d,.]+)?\s*(?<operator>\S+)\s*(?<limit2>[-\d,.]+)?]");
-                Match limitMatch = limitRegex.Match(match.Groups["limits"].Value);
+                Match limitMatch = _limitRegex.Match(match.Groups["limits"].Value);
                 if (limitMatch.Groups["limit1"].Success && limitMatch.Groups["limit2"].Success)
                 {
                     // Use InvariantCulture because Lauris always outputs dots as decimal separator
@@ -203,6 +198,11 @@ namespace zaaReloaded2.Importer.ZaaImporter
 
         #region Fields
 
+        static readonly Regex _numericalRegex = new Regex(
+            @"(?<name>[^:]+):\s*(?<value>[\d,.]+)\s*(?<limits>\[[^\]]+])?\s*(?<unit>[^;]+)?");
+        static readonly Regex _categoricalRegex = new Regex(
+            @"(?<name>[^:]+):\s*(?<value>[^[;]+)\s*(\[(?<normal>[^\]]+)])?");
+        static readonly Regex _limitRegex = new Regex(@"\[(?<limit1>[-\d,.]+)?\s*(?<operator>\S+)\s*(?<limit2>[-\d,.]+)?]");
         static readonly Regex _materialRegex = new Regex(@"\((?<material>(SU|PU))\)");
 
         #endregion