Ribosomal RNA
Recently, a number of studies have used molecular methods such as DNA fingerprinting or sequencing to study the diversity of organisms in soda lakes. These methods are based on DNA extracted directly from the environment and thus do not require microorganisms to be cultured. This is a major advantage, as culturing of novel microorganisms is a laborious technique known to seriously bias the outcome of diversity studies, since only about one in a hundred organisms can be cultured using standard techniques. For microorganisms, the phylogenetic marker gene Small Subunit (SSU) Ribosomal RNA is typically targeted, due to its good properties such as existence in all cellular organisms and ability to be used as a "molecular clock" to trace the evolutionary history of an organism. For instance, 16S ribosomal RNA gene clone libraries revealed that the bacterial community of the lake with the highest salinity was characterized by a higher recent accelerated diversification than the community of a freshwater lake, whereas the phylogenetic diversity in the hypersaline lake was lower than that in a freshwater lake. Culture-independent surveys have revealed that the diversity of microorganisms in soda lakes is very high, with species richness (number of species present) of individual lakes often rivaling that of freshwater ecosystems.