RNA Extraction , Separation , and

RNA is a powerful biological material. It is an active molecule that is directly involved in performing or controlling many biological functions. Unlocking the role of the various types of RNA present in biological cellular processes is critical to developing new methods of diagnosis and understanding and treating disease. New research is being reported daily that someday will lead to new drugs or methods of treating disease. Indeed, some of the work is so promising that it is hoped that a range of diseases will someday be effectively treated and cured. In any case, understanding RNA and its function is one of the keys to understanding life. There are many different types of RNA, each of which carries out diverse and important functions in the cell, as shown on the book cover and in Figure 1.1. The need to extract and understand the roles of these RNAs is important not only for an understanding of biology but also for developing therapeutics. This particular fi gure was chosen as the book cover because it illustrates the complexity and importance of RNA in functional mechanisms within the cell. To name a few, RNAs have been shown to function in transcription (pri-RNA, mRNA), splicing (snRNA), translation (tRNA, tmRNA), and post-transcription regulation (siRNA, miRNA). Each type and function of RNA is described in Chapter 2 of this book, while each pathway is discussed in more detail in Chapter 7. Unlike DNA – which is quite rugged – RNA is transient. RNA is also fragile, elusive, and diffi cult to recover. Proteins are expressed from DNA using RNA, with the cell carefully controlling which proteins are active, largely through overseeing the synthesis and degradation of RNA. The expression of DNA through RNA to produce new proteins could not be accomplished if the " old " RNA were still present from previous expressions of proteins; consequently, the cells routinely remove the " old " RNA by degrading it with RNase enzymes. Unfortunately, the RNase that is present for biological cellular function can also make RNA collection diffi cult, and any procedure employed for such collection and use must take this into account.