Lab Rats at Las Cruces by Amanda Strong

           

            We have come to the end of the semester here at the Las Cruces Biological Station. The last week has been primarily centered on the research of all the different groups. Due to the slowing down of the semester, the only reasonable topic to bring up is the research itself! Our group was tasked with the topic of “plant-based soaps.” Our instructions were to find local plants that contain chemicals called saponins, and see if they could be used to replace typical soap. Saponins are thought to be the main ingredient that allows the dirt and bacteria to be swept off of your skin. Learning the fact that saponins did not kill bacteria, but lifted and dragged the bacteria off the skin, is what encouraged us to go with the technique of handwashing in the lab.

The portions of each treatment used in our experiment. In order from top to bottom: PF, Clidemia hirta, Yucca elephantipes, and Phytolacca Rivinoides. *the species name for PF is undisclosed due to privacy rights.

            On the same night we were assigned our task, we all sat together hypothesizing about how we would test our new ideas. We concluded that we would use the plants to wash our hands – the same way we would with soap. How would we check to see if this worked? We would check bacterial growth on our hands from before washing and after washing. We also wanted to use two controls to see how effective our plants really were: Protex© antibacterial soap and plain tap water. Our plan worked out well. We researched four plants: Phytolacca rivinoides, Clidemia hirta, Yucca elephantipes, and PF (shown in the photo above) that are known to have high saponin content and did exactly what we had planned (well… more or less). We washed our hands with these plants and with the controls (sounds a lot simpler than it actually was) and watched the bacteria grow…or not grow.

            Our results were surprising! None of the treatments worked better than any of the others – meaning that none of the plants worked better than water, and neither did the Protex© antibacterial soap (see chart below). The good thing is that each of them did, indeed, decrease the bacterial load on our hands. The group had to chalk-up our results to good handwashing technique and clean water as the fundamental necessities when it comes to handwashing! Of course, there are many implications in the lab that could have skewed our results and we have plenty of ideas for future research.

            It is a bittersweet moment, because a part of me is relieved the semester is over, but another part of me would have really liked to continue the research and answer the questions we now have. Perhaps, next semester, a different group will pick up where we left off!

Grey bars = bacterial load before handwashing. Black bars = bacterial load after washing. Each treatment shows a decrease in bacteria overall, but there is no significant difference between how well each treatment worked. In order from left to right: PF, Phytolacca rivinoides, Clidemia hirta, Yucca elephantipes, Protex© soap, and water.