Early detection of malignant tumours, or their precursor lesions, can dramatically improve patient outcome. High risk
human Papillomavirus (HPV), particularly HPV16, infection can lead to the initiation and development of uterine
cervical neoplasia. Bearing this in mind the identification of the effects of HPV infection may have clinical value. In this
manuscript we investigate the application of Raman microspectroscopy to detect the presence of HPV in cultured cells
when compared with normal cells. We also investigate the effect of sample fixation, which is a common clinical practice,
on the ability of Raman spectroscopy to detect the presence of HPV. Raman spectra were acquired from Primary Human
Keratinocytes (PHK), PHK expressing the E7 gene of HPV 16 (PHK E7) and CaSki cells, an HPV16 containing cervical
carcinoma derived cell line. The average Raman spectra display variations, mostly in peaks relating to DNA and
proteins, consistent with HPV gene expression and the onset of neoplasia in both live and fixed samples. Principle
component analysis was used to objectively discriminate between the cells types giving sensitivities up to 100% for the
comparison between PHK and CaSki. These results show that Raman spectroscopy can discriminate between cell lines
representing different stages of cervical neoplasia. Furthermore Raman spectroscopy was able to identify cells expressing
the HPV 16 E7 gene suggesting the approach may be of value in clinical practice. Finally this technique was also able to
detect the effects of the virus in fixed samples demonstrating the compatibility of this technique with current cervical
screening methods. However if Raman spectroscopy is to make a significant impact in clinical practice the long
acquisition times must be addressed. In this report we examine the potential for beam shaping and advanced to improve
the signal to noise ration hence subsequently facilitating a reduction in acquisition time.
Optical binding may arise due to interplay between light scattering and refraction creating equilibrium positions for particles in a self-consistent manner. Binding is observed for the first time in biological cells within a dual beam fiber trap.
Raman Tweezers Micro Spectroscopy has become an important and versatile technique in recent years. The technique is the amalgamation of optical tweezers and traditional Raman spectroscopy. The combination of these two well established techniques has brought key advantages in the studies of many different physical and biological systems from studying drug distribution in cells to measuring the size of aerosol particles. In this paper we present our Raman Tweezers system and discuss its advantages over conventional Raman systems, also discussed in this section is the parameters which effect collection of Raman scattered light using the ability of the optical tweezers to stack micro spheres. Finally we discuss how to extend further the functionality of the Raman tweezers technique by decoupling the trapping and excitation with the use of a fibre optical light force trap.