The Lowry Method of Protein Assay is an effective alternative to point count or culture methods to determine the relative abundance of microorganisms in geologic samples. Results of this project show that the outcome of the Lowry assay is not affected by the constituents of a sandstone reservoir and that a relationship exists between microbes and clay minerals. Core samples were taken from the Carter sandstone at the North Blowhorn Creek Unit in Lamar County, Alabama. Samples were chosen based on mineralogic heterogeneity. The samples were placed in an anaerobic glove bag and given nutrients to induce the growth of in situ microorganisms. Samples were then assayed. Results of the protein assays show that the Lowry Method of Protein Assay is effective in determining protein concentrations in geologic samples with varying mineralogies. The assays also indicated that samples with abundant clay minerals show the greatest amount of microbial growth.