Adhesion Toxicity Assay

Set up an adhesion toxicity assay using 11 different brands of adhesive. A complete list of the different adhesives will follow in a future post.
The purpose of this study is to gauge the toxic effects of different adhesives on the Blaptica dubia (dubia) cockroach. This information will be invaluable for use in our in vivo catheter biofilm assay using the dubia roaches. In a pilot study, we found a significant difference in toxicological effect on the roaches depending on which type of adhesive that was used to seal the wound created from catheter insertion, with death and lethargy being most notable.

For this study 120 juvinile dubia roaches weighing between 0.4 to 1.0 grams were utilized. Each treatment (11 different adhesives and 1 wound control [no adhesive]) was performed in octuplicate (8x).
Roaches were semi-anesthetized by placing them on ice for 5 minutes (while they were inside a container). The ventral abdomen section of each roach was wiped with Isopropyl alcohol and allowed to dry for 30 seconds. Roughly a 2 mm deep subcutaneous wound was created using a sterile 22 gauge syringe needle. Injection site was at the 2nd or 3rd tergum section from the posterior end of the roach and went in the anterior direction for the 2 mm distance. The needle was removed and and aseptically stored for use on the next roach of that same treatment group. A single drop of adhesive was applied to where the puncture wound was made on the ventral side of the roach from the needle. No more adhesive was applied than necessary to seal the wound. No adhesive was applied to the roaches in the control treatment group after the wound was created.

Roaches were transferred to multi-purpose mini-cups (generally used for condiments [pictured at right]) with the lid put on. Each individual roach was put into their own mini-cup. Roaches were incubated upside down at room temperature for 10 minutes as they came out of anesthetization inside the mini-cup. After adhesive had dried, roaches were flipped over to their proper orientation and each treatment group was transferred to a larger container with a lid. In other words, there were two levels of containment for each roach: the mini-cup and the larger container with lid for each treatment group. All the treatments were transferred to the 37 C walk in incubator.

Survival will be monitored after 24 hours of incubation at 37 C.

//EWW