Lab Notes on: Dr. Sara Zapico
Gabrielle Alli's notes on Dr. Sara Zapico, a professor of chemistry and environmental science at New Jersey Institute of Technology.
Dr. Sara Zapico is an assistant professor in chemistry and environmental science at New Jersey Institute of Technology. She is also the principal investigator of the NJIT-associated Interdisciplinary Forensics and Biomedical Sciences Lab, otherwise known as ForenBioS. Dr. Zapico’s interest in forensics manifested at a young age, sparked by Agatha Christie novels and a mini crime lab game, pushing her towards this career ever since. She went on to earn multiple degrees from the University of Oviedo in Spain, focusing on biological science, biochemistry, and education. Remaining true to her lifelong dream of being a forensic scientist, Dr. Zapico would later complete her MS in forensic anthropology and genetics at University of Granada, followed by a PhD in biochemistry from the Institute for Cancer Research of Principado de Asturias.
Aside from teaching at NJIT and working at ForenBioS, Dr. Zapico does research with the Smithsonian Institution. Her investigations contribute to exhibitions concerning forensic anthropology with biochemical applications. Her colleagues at the Institution participate in and lead a wide variety of research that contributes to the fascinating collections on display.
Beginning in August 2021, Dr. Zapico continued her ventures in forensic research through the opening of ForenBioS. Their main research line is to improve age-at-death estimation based on the biochemical basics of aging. It can be difficult to determine the actual age of fully-developed adult skeletons, due to the lack of growing markers. The best estimations offered are often in a broad ten-year range, i.e. 30 to 40 year old remains, which can complicate solving situations such as missing person cases. Dr. Zapico and her lab colleagues are working to make these estimations more precise, by identifying methylation patterns that correlate with age1. They mainly use teeth to obtain these patterns, due to the ease of obtaining them and durability of their structure over time.
Epigenetics focuses on how behaviors and environment affect your traits, through its alternative impact on your genetic code. Rather than altering your genetic code itself, epigenetic changes transform the way it is read through “tags.” These tags result in DNA either tightly coiling or loosely fitting around histone proteins. Methyl groups are one type of tag that can result in repression of genes (caused by tightness) or expression of genes (caused by looseness).Another research line of ForenBioS is DNA isolation and characterization from challenging samples. One of their first forensic research projects was recovering DNA from bitten foods2. During home invasions, some suspects will not only steal things but also eat food found in the household. Dr. Zapico’s team strived to simulate and improve the process of identifying suspects through these trace quantities, utilizing apples, chocolate donuts, and cheese. They noticed how high DNA concentration did not always correlate with high DNA purity upon extraction, as the latter varied depending on the type of food a sample was extracted from. It was concluded that investigations utilizing this means of collecting evidence should be aware of its potential complications when identifying suspects.
A third research line is related to body fluid identification, working with samples such as semen, blood, and saliva. This work can help validate testing used in forensics to identify an individual based on DNA samples extracted from these fluids. Dr. Zapico’s team worked with a variety of fabrics, including denim, cotton, and polyester, to find out if it was easier to detect body fluids in one type of fabric over others3. They used DNA quantification and profiling techniques to analyze samples. Polyester was found to be the best material for both body fluid identification and DNA analysis. The team then furthered their research after this conclusion, testing how month-long exposure to tropical weather impacted the detection of DNA derived from blood, semen, and saliva found in polyester. Tropical weather consists of warm weather and storms, both of which can impact the concentration and purity of DNA remaining on a textile. Blood was found to be the most optimal for both sample collection and DNA processing.
DNA profiling, also referred to as genetic profiling, is the means by which a person’s unique genetic pattern is determined. These patterns can be useful for identifying an unknown individual when compared with known samples. The four steps of DNA profiling are extraction, quantification, amplification, and electrophoresis.ForenBioS is currently furthering its work in each of its research lines, grateful to have received funding for five projects in progress. Improving age estimation techniques continues to be an area of interest for this lab, contributing to advancements necessary to the field of forensics. They also aim to refine the correlation between genetic traits inferred from DNA and facial approximation technology. Despite the huge variety in research being done at ForenBioS, Dr. Zapico tells all students working at the lab the same thing: in whatever their subject is, their genuine interest and willingness to learn is the most important aspect of their process. She believes that these two things, combined with openness to collaborate, are what make a project successful. Further, she says that you must love what you are doing, whether it is research or another field, to be motivated and satisfied furthering yourself in it.