Experiment 2 Multi-dose BAC sterile 30days

Introduction

Researchers often use a branded form of a multi-dose vial of 30ml BAC water. According to USP guidelines this vial would expire 28 days after its first use. I have two of these vials which began use on 6/3/24 & 8/25/24.

Do multi-dose vials maintain sterility after being used in multiple experiments aseptically?

Methods

1. Multi-dose vials:
   1. About half of the 30ml BAC was used in multiple research protocols.
   2. Aseptic technique was maintained by always cleaning vial plunger with alcohol pad.
   3. Vials were used in a normal household countertop environment (not in a laminar airflow hood).
   4. Vials were discontinued after about a month.
   5. Vials were kept at room temperature in a dark environment for over 6 months after discontinued use.
2. 0.5ml of BAC was each added to 2 different culture plates ideal to rule bacterial, yeast, and mold growth.
3. Culture plates were incubated for 10 days. Fig 1

Results

No bacterial, yeast, and mold growth observed after 10 days of incubation. Fig 2, Fig 3

Discussion

Benzyl alcohol in BAC water is bacteriostatic and not a bactericide meaning it should prevent bacterial growth but often won’t kill it. These multi-use vials maintained sterility for over 6 months after being access multiple times. While this experiment is limited in only 2 vials were available for testing, it was surprising to see that vial sterility was maintained for a long period of time after being used for various research protocols.

Supplimental

Figure 1

Figure 2

Figure 3