The researchers analyzed the glutelin proteins in different types of rice using a method called SDS-PAGE. They found that the glutelin proteins can be grouped into three categories based on their sizes. There are distinct differences in the patterns of these proteins between different types of rice, such as cultivated and wild rice. The patterns can help classify rice species and ecotypes. For example, indica rice has a different glutelin pattern compared to japonica rice, while javanica rice is similar to upland rice. This study suggests that the patterns of glutelin proteins in rice can be used as a tool to identify and classify different types of rice.