instruction:
In this task, you are given a sentence from the research paper and your task is to classify the given sentence into the following categories: Background (Why is this problem important? What relevant works have been created before? What is still missing in the previous works? What are the high-level research questions? How might this help other research or researchers?), Purpose (What specific things do the researchers want to do? What specific knowledge do the researchers want to gain? What specific hypothesis do the researchers want to test?), Method (How did the researchers do the work or find what they sought? What are the procedures and steps of the research?), or Finding (What did the researchers find out? Did the proposed methods work? Did the thing behave as the researchers expected?). 
question:
Within these systems , monoclonal aptamer microbeads can be individually generated and assayed to assess aptamer candidate fitness thereby helping eliminate stochastic effects which are common to classical SELEX techniques.
answer:
background


question:
we noticed that some fecal viruses generated plaques > 100 times as large as inoculum viruses.
answer:
finding


question:
We identified factors associated with the Middle East Respiratory Syndrome-Coronavirus ( MERS-CoV ) infection among suspected cases presented with sign and symptoms of upper respiratory infection or exposure to the virus.
answer:

purpose