Raman spectroscopy can be used to measure the chemical composition of a sample, which can in turn be used to extract biological information. Many materials have characteristic Raman spectra, which means that Raman spectroscopy has proven to be an effective analytical approach in geology, semiconductor, materials and polymer science fields. The application of Raman spectroscopy and microscopy within biology is rapidly increasing because it can provide chemical and compositional information, but it does not typically suffer from interference from water molecules. Analysis does not conventionally require extensive sample preparation; biochemical and structural information can usually be obtained without labeling. In this protocol, we aim to standardize and bring together multiple experimental approaches from key leaders in the field for obtaining Raman spectra using a microspectrometer. As examples of the range of biological samples that can be analyzed, we provide instructions for acquiring Raman spectra, maps and images for fresh plant tissue, formalin-fixed and fresh frozen mammalian tissue, fixed cells and biofluids. We explore a robust approach for sample preparation, instrumentation, acquisition parameters and data processing. By using this approach, we expect that a typical Raman experiment can be performed by a nonspecialist user to generate high-quality data for biological materials analysis.

/pdf/using-raman-spectroscopy-to-characterize-biological-56ndts7qm5.pdf

Using Raman spectroscopy to characterize biological materials

The ability to diagnose the early onset of disease, rapidly, non-invasively and unequivocally has multiple benefits. These include the early intervention of therapeutic strategies leading to a reduction in morbidity and mortality, and the releasing of economic resources within overburdened health care systems. Some of the routine clinical tests currently in use are known to be unsuitable or unreliable. In addition, these often rely on single disease markers which are inappropriate when multiple factors are involved. Many diseases are a result of metabolic disorders, therefore it is logical to measure metabolism directly. One of the strategies employed by the emergent science of metabolomics is metabolic fingerprinting; which involves rapid, high-throughput global analysis to discriminate between samples of different biological status or origin. This review focuses on a selective number of recent studies where metabolic fingerprinting has been forwarded as a potential tool for disease diagnosis using infrared and Raman spectroscopies.

/pdf/metabolic-fingerprinting-in-disease-diagnosis-biomedical-3o8sqizbfh.pdf

Metabolic fingerprinting in disease diagnosis: biomedical applications of infrared and Raman spectroscopy.

http://xrm.phys.northwestern.edu/research/pdf_papers/2006/chan_biophysj_2006.pdf

Micro-Raman Spectroscopy Detects Individual Neoplastic and Normal Hematopoietic Cells

Raman spectroscopy for medical diagnostics — From in-vitro biofluid assays to in-vivo cancer detection ☆

Guidelines for Preventive Activities in General Practice

Raman spectroscopy (RS) is an optical technique that provides an objective method of pathological diagnosis based on the molecular composition of tissue. Studies have shown that the technique can accurately identify and grade prostatic adenocarcinoma (CaP) in vitro. This study aimed to determine whether RS was able to differentiate between CaP cell lines of varying degrees of biological aggressiveness. Raman spectra were measured from two well-differentiated, androgen-sensitive cell lines (LNCaP and PCa 2b) and two poorly differentiated, androgen-insensitive cell lines (DU145 and PC 3). Principal component analysis was used to study the molecular differences that exist between cell lines and, in conjunction with linear discriminant analysis, was applied to 200 spectra to construct a diagnostic algorithm capable of differentiating between the different cell lines. The algorithm was able to identify the cell line of each individual cell with an overall sensitivity of 98% and a specificity of 99%. The results further demonstrate the ability of RS to differentiate between CaP samples of varying biological aggressiveness. RS shows promise for application in the diagnosis and grading of CaP in clinical practise as well as providing molecular information on CaP samples in a research setting.

/pdf/the-use-of-raman-spectroscopy-to-differentiate-between-4b89ockbrr.pdf

The use of Raman spectroscopy to differentiate between different prostatic adenocarcinoma cell lines

Raman spectroscopy is an optical technique, which provides a measure of the molecular composition of tissue. Raman spectra were recorded in vitro from both benign and malignant prostate biopsies, and used to construct a diagnostic algorithm. The algorithm was able to correctly identify each pathological group studied with an overall accuracy of 89%. The technique shows promise as a method for objectively grading prostate cancer.

/pdf/the-use-of-raman-spectroscopy-to-identify-and-grade-2h933uw4tf.pdf

The use of Raman spectroscopy to identify and grade prostatic adenocarcinoma in vitro

OBJECTIVE

To determine whether Raman spectroscopy can be used to differentiate between normal, inflammatory and malignant bladder pathologies in vitro, and secondly if it can used to grade and stage transitional cell carcinoma (TCC).



MATERIALS AND METHODS

In all, 1525 Raman spectra were measured from 75 bladder samples comprising normal bladder, cystitis, carcinoma in situ (CIS), TCC and adenocarcinoma. Multivariate analysis was applied to the spectral dataset to construct diagnostic algorithms; these were then tested for their ability to determine the histological diagnosis of each sample from its Raman spectrum.



RESULTS

The diagnostic algorithms could be used to accurately differentiate among the pathological groups, in particular, a three-group algorithm differentiated among normal bladder, cystitis and TCC/CIS with sensitivities and specificities of > 90%. Algorithms could also accurately characterize TCC in terms of splitting them into low (G1/G2) or high (G3) grade and superficial (pTa) or invasive (pT1/pT2) stage.



CONCLUSION

Raman spectroscopy can be used to accurately identify and grade/stage TCC in vitro. The technique therefore shows promise for use as an objective method to assist the pathologist in assessing bladder pathologies. Raman spectroscopy also has potential to provide immediate pathological diagnoses during surgical procedures. Following the promising results of this in vitro study, in vivo cystoscopic studies are planned.

The use of Raman spectroscopy to identify and characterize transitional cell carcinoma in vitro.

Optical diagnostics in urology: current applications and future prospects.

Raman spectroscopy is an optical technique able to interrogate biological tissues, giving us an understanding of the changes in molecular structure that are associated with disease development. The Kerr-gated Raman spectroscopy technique uses a picosecond pulsed laser as well as fast temporal gating of collected Raman scattered light. Prostate samples for this study were obtained by taking a chip at the transurethral resection of the prostate (TURP), and bladder samples from a biopsy taken at transurethral resection of bladder tumor (TURBT) and TURP. Spectra obtained through the bladder and prostate gland tissue, at different time delays after the laser pulse, clearly show change in the spectra as depth profiling occurs, eventually showing signals from the uric acid cell and urea cell, respectively. We show for the first time, using this novel technique, that we are able to obtain spectra from different depths through both the prostate gland and the bladder. This has major implications in the future of Raman spectroscopy as a tool for diagnosis. With the help of Raman spectroscopy and Kerr gating, it may be possible to pick up the spectral differences from a small focus of adenocarcinoma of the prostate gland in an otherwise benign gland, and also stage the bladder cancers by assessing the base of the tumor post resection.

https://www.spiedigitallibrary.org/journals/Journal-of-Biomedical-Optics/volume-10/issue-04/044006/Use-of-picosecond-Kerr-gated-Raman-spectroscopy-to-suppress-signals/10.1117/1.1991848.pdf

Mark Wright

Papers

The use of Raman spectroscopy to differentiate between different prostatic adenocarcinoma cell lines

The use of Raman spectroscopy to identify and grade prostatic adenocarcinoma in vitro

The use of Raman spectroscopy to identify and characterize transitional cell carcinoma in vitro.

Optical diagnostics in urology: current applications and future prospects.

Use of picosecond Kerr-gated Raman spectroscopy to suppress signals from both surface and deep layers in bladder and prostate tissue