The document describes an ELISA experiment to detect the presence of proteins in blood or fluids. Students worked in pairs to mix and share samples between groups using a 12-well strip. They transferred samples to wells, washed wells with buffer, and added primary, secondary, and substrate antibodies. A color change indicated infection with the target virus, in this case HIV. Students used Excel to track positive and negative results, discovering that person 10 had HIV and infected others based on two shared samples testing positive.

1. University of Puerto Rico<br />Cayey Campus<br />Jessica Díaz Rivera<br />Prof. Elena Gonzalez<br />RISE Program<br />Paragraph # 11: ELISA-Enzyme Linked Immunosorbant Assay<br /> Enzyme Linked Immunosorbant Assay (ELISA) uses antibodies to detect the presence of a protein agent in your blood or body fluids. The objective of this experiment is to know how infectious diseases spread. First, the laboratory was done in pairs. Partners had to mix the samples and share them with other persons from another group. The 12-well strip used was labeled with three positive controls, three negative controls, and the remaining wells were labeled with the initials of each pair. We had to transfer 50 micro liters of the sample to the specific wells. We waited five minutes while all the proteins in the samples bound to the plastic wells. After transferring each sample, we had to wash the wells with PBSx-buffer. With a fresh tip we transferred 50 micro liters of the primary antibody (rabbit) into all 12-wells of the microplate strip. Later, we had to wait five minutes and repeat the washing procedure. With another fresh pipet tip, we added 50 micro liters of secondary antibody (goat), and again waited five minutes and re-washed the wells. At the end, we added 50 micro liters of the enzyme substrate (tetramethylbenzidine) into all 12-wells of the microplate. When the catalysis occurs, it reflects a change in color indicating that the person was infected with, in this case, the HIV virus. We used the Excel Program to construct a table with the number of positive or negative samples and the sharing partner. The conclusion was that the person who had HIV and infected the others was number 10. We discovered the person that had the virus and infected the others who shared the sample because in the table that we prepared in Excel Program, there's only two of the samples that gave positive values with the two persons that they shared.<br />