A robust and specific immune response is critical for the maintenance of organismal health. The immune response’s primary function is infection clearance; however, the outcome of an infection can vary greatly between individuals. This variation can be traced back to the combined effects of genetic background, environmental factors, and stochastic events. Understanding how these individual components influence the observed variation in immune response in Drosophila may help further our understanding of infection outcome in across metazoans, mammals, and plants. Here, I investigate sequence variation that leads to variation in immune response and propose to novel methods that will help investigate additional sources of variation. In Chapter 2, I quantify the relative contributions of changes in cis and trans to expression divergence in the Drosophila immune response. I show that the proportions of these changes are condition specific. In Chapter 3, I describe a novel method for the longitudinal monitoring of infection progression using autobioluminscent bacteria. I demonstrate the methods utility for linking individual infection histories to observed outcomes. Lastly in Chapter 4, I adapt a method for the cell specific chemical labeling of nascent RNA’s using an orthogonal chemical-genetic labeling system. I show preliminary results that suggest the method can specifically label RNA in a tissue specific manner and provide next steps for the application of this method fully in Drosophila.