Mixed Linkage Glucan (MLG, or (1,3;1,4)-ß-D glucan) is a component of cell walls for major cereal crops and is significant to food and beverage industries. To better understand genetic factors affecting MLG content in oats, this study investigates the presence of glucosidases likely to participate in MLG production. A glucosidase showing co-expression with CslF6—the primary gene responsible for MLG synthesis—could indicate a hand in MLG production by association. Reference genes for expression analysis as well as glucosidase candidates were first selected using in silico methods. In both cases, barley was used as model species because it has abundant public bioinformatic resources for in silico data mining, and it generates large amounts of MLG, like oats. Actin, malate dehydrogenase, and elongation factor 2, were validated in oat and barley as top reference genes. They were then used to compare the expression activity of the top glucosidase candidate gene, ßglux, with CslF6. ßglux was found to have increased activity with CslF6 during caryopsis development. It is a strong candidate for future transgenic experiments regarding its effect on MLG production.