This is a real-world medical entrance exam question, please give the true answer based on the question and selection. Topic name: None, Subject name: Surgery
Which one of the following preservative is used while packing catgut suture? 
Select and explain. 
A. Isopropyl alcohol, B. Colloidal iodine, C. Glutaraldehyde, D. Hydrogen peroxide
A: Isopropyl alcohol
Answer: A: Isopropyl alcohol 
Explanation: 10% isopropyl alcohol is the routine packing fluid used in packing catgut sutures. Catgut is available in glass tubes containing isopropyl alcohol and small quantity of water. Catgut is prepared from the intestine of sheep. Ref: Pharmaceutics By Dr. R. S. Gaud, Page 196; Veterinary Medicine/small animal clinician, Volume 72, Issues 1-6, Page 835.