T4 Bacteriophage Behavior on Paper: Stability after Drying and Long-Term Storage

Bacteriophages, virus that attack and potentially kill bacteria, have a great potential in both bacteria detection and eradication. One of the reasons is because of their specific interactions with the host bacteria. Being able to store bacteriophages on a solid substrate will open more possibility in their applications. Our research focuses on the drying and storing of T4 bacteriophages on paper. Paper, a cheap and ubiquitous substrate, can both be used in detection and as delivery vehicle for bacteria eradication. Here we report the influence of the drying technique on the survival of bacteriophages on paper. To further improve the survivability of the bacteriophages, stabilizers such as skim milk and polyethylene glycol were added prior to drying of the paper samples containing T4 bacteriophages. We tested several different drying methods namely slow and quick air-drying, heat-drying, and freeze-drying. We also studied both the short-term and long-term survival of dry bacteriophages on paper at room temperature. To better compare samples, we developed a method to quantify the area of clearing around a paper and compare those areas between samples taken at different days. We achieved the best results through the combination of air-drying and skim milk, which kept the bacteriophage active for 56 days.