All over the world, scientists working in academia, government and industry are actively engaged in the characterisation, screening and diagnosis of different pathological conditions. In addition, they use an array of analytical techniques to investigate molecular changes associated with the interaction of drugs, chemicals and environmental factors on different organisms. Ideally, the aim is to monitor the system of interest, without disturbing it, in a sensitive, rapid and automated manner at minimum cost. Vibrational spectroscopy is one of the few analytical techniques that meets all of these requirements. It offers both advantages and tremendous potential, but also has limitations and challenges.

The goal of this book is to show how a range of vibrational spectroscopic techniques can be used in the screening and diagnosis of different systems and conditions and to provide information about the latest experimental and computational approaches in current use. This book not only covers the well known near infrared (NIR), mid-infrared and Raman spectroscopic methods, but also includes a new vibrational technique, Terahertz (THz) spectroscopy. With the developments in technology for the recording of spectra and the analysis of data using chemometric methods, vibrational spectroscopy has proved attractive to scientists engaged in the study of complex systems such as biological cells, tissues and foodstuffs.

In contrast to other books in the field, which mainly discuss the applications of vibrational spectroscopy in biomedical and food sciences, this book includes several chapters related to the diagnosis and screening of different biological systems such as calcified tissues, dental tissues, stem cells, and forensic and aquatic science.

The organization of this book is as follows:

After a short introduction, some historical background and information on application trends in the first chapter, the second chapter focuses on the background to methodological approaches from experimental to computational analysis in vibrational spectroscopy and microspectroscopy. The next chapter examines the analysis of protein structure, with particular attention for the screening of proteins in cells and tissues by vibrational spectroscopy. The use of near-infrared spectroscopy for the characterisation of single molecules in complex biological fluids is presented in chapter 4.

One of the important advantages of vibrational spectroscopy, and one which makes it ideal for the study of a diverse range of complex systems, is the capacity to record spectra of solids/aggregates/suspensions. These cannot be readily analysed using other techniques, which require homogeneous solutions or well defined crystals etc. Vibrational spectroscopy has therefore been invaluable in the characterisation of the protein aggregates often associated with neurodegenerative protein misfolding diseases such as prion disease, Alzheimer's disease, Parkinson's disease, Huntington's disease etc. The use of infrared spectroscopy in neurodegenerative protein-misfolding diseases is discussed in chapter 5.

In recent years the immense medical potential of stem cells for treating diseases has been a major development. The characterisation of stem cells is very important for quality control and structure-function studies. Vibrational spectroscopy offers the possibility of characterising stem cells, and examples of such studies are provided in chapter 6. The potential of infrared spectroscopy in the diagnosis and screening of cancer has been an active field of research for at least the last two decades. Much progress has been made in this field and this is discussed in chapters seven, eight and nine.

The use of vibrational spectroscopy for imaging cells and tissues is another emerging field of research activity. The power of this approach is increasingly appreciated, and it may not be too long before vibrational spectral imaging becomes a specialist tool in hospitals for screening and diagnosis. Chapter 8 gives an example of how FTIR and FPA methods are being used to discriminate breast tissular structure.

The application of infrared spectroscopy in the screening and diagnosis of diabetes is covered in chapter 10. Characterisation of bone, cartilage and dental tissues by vibrational spectroscopy is covered in chapters 11 and 12, respectively. The usefulness of vibrational spectroscopy in the diagnosis and screening of aquatic environments is covered in chapter 13. The next chapter of the book discusses the applications of vibrational spectroscopy for the screening and characterisation of tissues in relation to forensics research. The emerging field of synchrotron-based vibrational spectroscopy and the use of synchrotron radiation based infrared spectroscopy in the diagnosis and screening of feed and food quality is presented in chapter 15.

Our choice of topics will hopefully give readers a general overview with a broad perspective of the investigation of tissues and cells for screening and diagnosis purposes using different vibrational spectroscopic methods. We also believe that the book will provide knowledge about how these techniques can be used in the early diagnosis of disease, which is a very important issue.

Throughout the book we have taken care to use the nomenclature recommended in the journal of Applied Spectroscopy, which can be found via the link below:

http://www.s-a-s.org/media/pdf/2010/03/17/apls-64-01-136.pdf.

We hope that the materials presented in this book offer a glimpse of the power of NIR mid-FTIR Raman THz spectroscopy for the screening diagnosis of pathological and environmental conditions, as well as for understanding the molecular basis of disease processes.

We would like to thank all the authors who contributed to this book. Finally, we would like to thank Nihal Simsek Ozek (PhD student) and Dr. Ceren Aksoy and Dr. Sara Banu Akkas (former PhD students) of Feride Severcan's laboratory, for their valuable support; they were always eager to help us by finding references, drawing diagrams, preparing the cover of the book etc.

Feride Severcan (Ankara, Turkey)

Parvez I. Haris (Leicester, UK)