diff --git a/wiki/pages/experiments.html b/wiki/pages/experiments.html
index 284190208a7b0fbb9565c07bcc9e6e5b34625e68..0a4ba52ac909796b6c93d39aa59d94a98c640ee0 100644
--- a/wiki/pages/experiments.html
+++ b/wiki/pages/experiments.html
@@ -270,7 +270,13 @@
     </li>
     <li> Mutant MT plasmids were then purified and kept at -18°C. </li>
     </ol>
-  
+
+    <h3>Para-Nitrophenol butyrate (pNPB) Assay</h3>
+    <ol>
+        <li>Prepare 50mM pNPB stock solution and reaction buffer (45 mM Na<sub>2</sub>HPO<sub>4</sub>-HCl (pH 7.0), 90 mM NaCl, and 10% (v/v) DMSO)</li>
+        <li>The final reaction system contained protein samples (100-300 µg/ml), 2mM pNPB, and the reaction buffer.</li>
+        <li>The reaction system was incubated for 30 minutes at 250 rpm 37°C for all PETase related constructs</li>
+    </ol>
 
   <br>
   <h1 id="2" class="anchor">JUMP Assembly</h1>