 This can be accomplished by comparing various samples against molecular-weight size markers for qualitative analysis and against known amounts of protein standards for quantitative analysis.By coupling liquid chromatography with a variety of other immunodetection techniques such as serological proteome analysis (SERPA), it is possible to analyze the hydrophobicity, PI, relative mass, and antibody reactivity of antibodies within a given serum.Microarray analysis of various serums can be used as a means to identify changes in gene expression before, after, and during a given immune response.