Study of Minor Chromophores in Biological Tissues by Diffuse Optical Spectroscopy (Review)

Diffuse optical spectroscopy (DOS) is a rapidly advancing non-invasive diagnostic technique to investigate biological tissue, based on probing the target object with optical radiation in the visible and/or near-infrared wavelength range and detecting the diffusely scattered light from the tissue. The signals obtained through DOS provide extensive information about the biochemical composition of tissues due to the presence of light-absorbing compounds known as chromophores. To date, DOS is widely employed to detect major chromophores such as deoxygenated (Hb) and oxygenated (HbO₂) hemoglobin, water, lipids, and melanin. The concentrations of Hb and HbO₂ in biological tissues are highly significant in clinical research, as they offer valuable insights into tissue oxygenation status and enable the detection of hypoxia. However, biological tissues also contain less-studied chromophores — minor chromophores — which also contribute to the overall absorption spectrum. These include various globins, such as methemoglobin, carboxyhemoglobin, and myoglobin, as well as cytochromes and cytochrome c oxidase. Identifying minor chromophores using DOS is challenging due to their relatively low absorption contributions compared to major chromophores, as well as the limited understanding of their specific absorption spectra. Nevertheless, the simultaneous detection of both major and minor chromophores could provide a comprehensive understanding of metabolic processes within vascular, intracellular, and mitochondrial compartments of tissues. This would substantially expand the potential applications of DOS in both research and clinical studies. In this review we examine literature sources that explore the investigation of minor chromophores in biological tissues by DOS, discuss the role of major chromophores, and evaluate the potential for simultaneous detection of both major and minor chromophores with DOS.

1. Movasaghi Z., Rehman S., Rehman I.U. Raman spectroscopy of biological tissues. Appl Spectrosc Rev 2007; 42(5): 493–541, https://doi.org/10.1080/05704920701551530.
2. Xie S., Li H., Zheng W., Chia T.-C., Lee S., Huang Z. Principles and techniques for measuring optical parameters of biotissue. Lasers in medicine and dentistry: diagnostics and treatment 1996; 2887: 92–102, https://doi.org/10.1117/12.251937.
3. Hoshi Y., Yamada Y. Overview of diffuse optical tomography and its clinical applications. J Biomed Opt 2016; 21(9): 091312, https://doi.org/10.1117/1.JBO.21.9.091312.
4. Potapova E.V., Shupletsov V.V., Dremin V.V., Zherebtsov E.A., Mamoshin A.V., Dunaev A.V. In vivo time-resolved fluorescence detection of liver cancer supported by machine learning. Lasers Surg Med 2024; 56(10): 836–844, https://doi.org/10.1002/lsm.23861.
5. Fritsch C., Ruzicka T. Fluorescence diagnosis and photodynamic therapy in dermatology from experimental state to clinic standard methods. J Environ Pathol Toxicol Oncol 2006; 25(1–2): 425–439, https://doi.org/10.1615/jenvironpatholtoxicoloncol.v25.i1-2.270.
6. Khilov A.V., Sergeeva E.A., Kurakina D.A., Turchin I.V., Kirillin M.Yu. Analytical model of fluorescence intensity for the estimation of fluorophore localisation in biotissue with dual-wavelength fluorescence imaging. Quantum Electronics 2021; 51(2): 95–103, https://doi.org/10.1070/qel17503.
7. de Boer L.L., Molenkamp B.G., Bydlon T.M., Hendriks B.H., Wesseling J., Sterenborg H.J., Ruers T.J. Fat/water ratios measured with diffuse reflectance spectroscopy to detect breast tumor boundaries. Breast Cancer Res Treat 2015; 152(3): 509–518, https://doi.org/10.1007/s10549-015-3487-z.
8. Druzhkova I., Bylinskaya K., Plekhanov A., Kostyuk A., Kirillin M., Perekatova V., Khilov A., Orlova A., Polozova A., Komarova A., Lisitsa U., Sirotkina M., Shirmanova M., Turchin I. Effects of FOLFOX chemotherapy on tumor oxygenation and perfused vasculature: an in vivo study by optical techniques. J Biophotonics 2024, https://doi.org/10.1002/jbio.202400339.
9. Veluponnar D., de Boer L.L., Dashtbozorg B., Jong L.S., Geldof F., Guimaraes M.D.S., Sterenborg H.J.C.M., Vrancken-Peeters M.T.F.D., van Duijnhoven F., Ruers T. Margin assessment during breast conserving surgery using diffuse reflectance spectroscopy. J Biomed Opt 2024; 29(4): 045006, https://doi.org/10.1117/1.JBO.29.4.045006.
10. Skyrman S., Burström G., Lai M., Manni F., Hendriks B., Frostell A., Edström E., Persson O., Elmi-Terander A. Diffuse reflectance spectroscopy sensor to differentiate between glial tumor and healthy brain tissue: a proof-of-concept study. Biomed Opt Express 2022; 13(12): 6470–6483, https://doi.org/10.1364/BOE.474344.
11. Jules A., Means D., Troncoso J.R., Fernandes A., Dadgar S., Siegel E.R., Rajaram N. Diffuse reflectance spectroscopy of changes in tumor microenvironment in response to different doses of radiation. Radiat Res 2022; 198(6): 545–552, https://doi.org/10.1667/RADE-21-00228.1.
12. Hsu C.K., Tzeng S.Y., Yang C.C., Lee J.Y., Huang L.L., Chen W.R., Hughes M., Chen Y.W., Liao Y.K., Tseng S.H. Non-invasive evaluation of therapeutic response in keloid scar using diffuse reflectance spectroscopy. Biomed Opt Express 2015; 6(2): 390–404, https://doi.org/10.1364/BOE.6.000390.
13. Schelkanova I., Pandya A., Muhaseen A., Saiko G., Douplik A. Early optical diagnosis of pressure ulcers. In: Meglinski I. (editor). Biophotonics for medical applications. Woodhead Publishing; 2015; p. 347–375, https://doi.org/10.1016/B978-0-85709-662-3.00013-0.
14. Parvez M.A., Yashiro K., Nagahama Y., Tsunoi Y., Saitoh D., Sato S., Nishidate I. In vivo visualization of burn depth in skin tissue of rats using hemoglobin parameters estimated by diffuse reflectance spectral imaging. J Biomed Opt 2024; 29(2): 026003, https://doi.org/10.1117/1.JBO.29.2.026003.
15. Nguyen T., Kim S., Kim J.G. Diffuse reflectance spectroscopy to quantify the met-myoglobin proportion and meat oxygenation inside of pork and beef. Food Chem 2019; 275: 369–376, https://doi.org/10.1016/j.foodchem.2018.09.121.
16. Rossel R.A.V., Behrens T., Ben-Dor E., Chabrillat S., Demattê J.A.M., Ge Y., Gomez C., Guerrero C., Peng Y., Ramirez-Lopez L., Shi Z., Stenberg B., Webster R., Winowiecki L., Shen Z. Diffuse reflectance spectroscopy for estimating soil properties: a technology for the 21st century. European Journal of Soil Science 2022; 73(4): e13271, https://doi.org/10.1111/ejss.13271.
17. Beschastnov V.V., Ryabkov М.G., Pavlenko I.V., Bagryantsev М.V., Dezortsev I.L., Kichin V.V., Baleyev М.S., Maslennikova А.V., Orlova А.G., Kleshnin М.S., Turchin I.V. Current methods for the assessment of oxygen status and biotissue microcirculation condition: diffuse optical spectroscopy (review). Sovremennye tehnologii v medicine 2018; 10(4): 183, https://doi.org/10.17691/stm2018.10.4.22.
18. Turchin I.V. Methods of biomedical optical imaging: from subcellular structures to tissues and organs. Physics-Uspekhi 2016; 59(5): 487–501, https://doi.org/10.3367/ufne.2015.12.037734.
19. Perekatova V., Kostyuk A., Kirillin M., Sergeeva E., Kurakina D., Shemagina O., Orlova A., Khilov A., Turchin I. VIS-NIR diffuse reflectance spectroscopy system with self-calibrating fiber-optic probe: study of perturbation resistance. Diagnostics (Basel) 2023; 13(3): 457, https://doi.org/10.3390/diagnostics13030457.
20. Budylin G.S., Davydov D.A., Zlobina N.V., Baev A.V., Artyushenko V.G., Yakimov B.P., Shirshin E.A. In vivo sensing of cutaneous edema: a comparative study of diffuse reflectance, Raman spectroscopy and multispectral imaging. J Biophotonics 2022; 15(1): e202100268, https://doi.org/10.1002/jbio.202100268.
21. Li S., Ardabilian M., Zine A. Quantitative analysis of skin using diffuse reflectance for non-invasive pigments detection. In: Proceedings of the 16th International Joint Conference on Computer Vision, Imaging and Computer Graphics Theory and Applications (VISIGRAPP 2021). Vol. 4. 2021; p. 604–614, https://doi.org/10.5220/0010326806040614.
22. Chae E.Y., Kim H.H., Sabir S., Kim Y., Kim H., Yoon S., Ye J.C., Cho S., Heo D., Kim K.H., Bae Y.M., Choi Y.W. Development of digital breast tomosynthesis and diffuse optical tomography fusion imaging for breast cancer detection. Sci Rep 2020; 10(1): 13127, https://doi.org/10.1038/s41598-020-70103-0.
23. Zhang Q., Jiang H. Three-dimensional diffuse optical imaging of hand joints: system description and phantom studies. Opt Lasers Eng 2005; 43: 1237–1251, https://doi.org/10.1016/j.optlaseng.2004.12.007.
24. Hoi J.W., Kim H.K., Fong C.J., Zweck L., Hielscher A.H. Non-contact dynamic diffuse optical tomography imaging system for evaluating lower extremity vasculature. Biomed Opt Express 2018; 9(11): 5597–5614, https://doi.org/10.1364/BOE.9.005597.
25. Kurakina D., Perekatova V., Sergeeva E., Kostyuk A., Turchin I., Kirillin M. Probing depth in diffuse reflectance spectroscopy of biotissues: a Monte Carlo study. Laser Phys Lett 2022; 19: 035602, https://doi.org/10.1088/1612-202X/ac4be8.
26. Blaney G., Sassaroli A., Fantini S. Dual-slope imaging in highly scattering media with frequency-domain near-infrared spectroscopy. Opt Lett 2020; 45(16): 4464–4467, https://doi.org/10.1364/OL.394829.
27. Farrell T.J., Patterson M.S., Wilson B. A diffusion theory model of spatially resolved, steady-state diffuse reflectance for the noninvasive determination of tissue optical properties in vivo. Med Phys 1992; 19(4): 879–888, https://doi.org/10.1118/1.596777.
28. Sergeeva E., Kurakina D., Turchin I., Kirillin M. A refined analytical model for reconstruction problems in diffuse reflectance spectroscopy. J Innov Opt Health Sci 2024; 17(05): 2342002, https://doi.org/10.1142/S1793545823420026.
29. Post A.L., Faber D.J., Sterenborg H.J.C.M., van Leeuwen T.G. Subdiffuse scattering and absorption model for single fiber reflectance spectroscopy. Biomed Opt Express 2020; 11(11): 6620–6633, https://doi.org/10.1364/BOE.402466.
30. Orlova A., Perevalova Y., Pavlova K., Orlinskaya N., Khilov A., Kurakina D., Shakhova M., Kleshnin M., Sergeeva E., Turchin I., Kirillin M. Diffuse optical spectroscopy monitoring of experimental tumor oxygenation after red and blue light photodynamic therapy. Photonics 2022; 9(1): 19, https://doi.org/10.3390/PHOTONICS9010019.
31. Sekar S., Lanka P., Farina A., Mora A.D., Andersson-Engels S., Taroni P., Pifferi A. Broadband time domain diffuse optical reflectance spectroscopy: a review of systems, methods, and applications. Appl Sci 2019; 9(24): 5465, https://doi.org/10.3390/app9245465.
32. Gioux S., Mazhar A., Cuccia D.J. Spatial frequency domain imaging in 2019: principles, applications, and perspectives. J Biomed Opt 2019; 24(7): 1–18, https://doi.org/10.1117/1.JBO.24.7.071613.
33. Zhou X., Xia Y., Uchitel J., Collins-Jones L., Yang S., Loureiro R., Cooper R.J., Zhao H. Review of recent advances in frequency-domain near-infrared spectroscopy technologies [Invited]. Biomed Opt Express 2023; 14(7): 3234–3258, https://doi.org/10.1364/BOE.484044.
34. van Veen R.L., Sterenborg H.J., Pifferi A., Torricelli A., Chikoidze E., Cubeddu R. Determination of visible near-IR absorption coefficients of mammalian fat using time- and spatially resolved diffuse reflectance and transmission spectroscopy. J Biomed Opt 2005; 10(5): 054004, https://doi.org/10.1117/1.2085149.
35. Nogueira M.S., Maryam S., Amissah M., Lu H., Lynch N., Killeen S., O’Riordain M., Andersson-Engels S. Evaluation of wavelength ranges and tissue depth probed by diffuse reflectance spectroscopy for colorectal cancer detection. Sci Rep 2021; 11(1): 798, https://doi.org/10.1038/s41598-020-79517-2.
36. Turchin I., Beschastnov V., Peretyagin P., Perekatova V., Kostyuk A., Orlova A., Koloshein N., Khilov A., Sergeeva E., Kirillin M., Ryabkov M. Multimodal optical monitoring of auto- and allografts of skin on a burn wound. Biomedicines 2023; 11(2): 351, https://doi.org/10.3390/biomedicines11020351.
37. Bydlon T.M., Nachabé R., Ramanujam N., Sterenborg H.J., Hendriks B.H. Chromophore based analyses of steady-state diffuse reflectance spectroscopy: current status and perspectives for clinical adoption. J Biophotonics 2015; 8(1-2): 9–24, https://doi.org/10.1002/jbio.201300198.
38. Jacques S.L. Optical properties of biological tissues: a review. Phys Med Biol 2013; 58(11): R37–R61. Corrected and republished from: Phys Med Biol 2013; 58(14): 5007–5008, https://doi.org/10.1088/0031-9155/58/11/R37.
39. Nelson D.L., Cox M.M. Lehninger Biochemie. Springer Berlin Heidelberg, Berlin, Heidelberg; 2001.
40. Assorted Spectra. URL: https://omlc.org/spectra/index.html.
41. Wada H., Yoshizawa N., Ohmae E., Ueda Y., Yoshimoto K., Mimura T., Nasu H., Asano Y., Ogura H., Sakahara H., Goshima S. Water and lipid content of breast tissue measured by six-wavelength time-domain diffuse optical spectroscopy. J Biomed Opt 2022; 27(10): 105002, https://doi.org/10.1117/1.JBO.27.10.105002.
42. Efendiev K., Alekseeva P., Linkov K., Shiryaev A., Pisareva T., Gilyadova A., Reshetov I., Voitova A., Loschenov V. Tumor fluorescence and oxygenation monitoring during photodynamic therapy with chlorin e6 photosensitizer. Photodiagnosis Photodyn Ther 2024; 45: 103969, https://doi.org/10.1016/j.pdpdt.2024.103969.
43. Nachabé R., Evers D.J., Hendriks B.H., Lucassen G.W., van der Voort M., Wesseling J., Ruers T.J. Effect of bile absorption coefficients on the estimation of liver tissue optical properties and related implications in discriminating healthy and tumorous samples. Biomed Opt Express 2011; 2(3): 600–614, https://doi.org/10.1364/BOE.2.000600.
44. Meineke G., Hermans M., Klos J., Lenenbach A., Noll R. A microfluidic opto-caloric switch for sorting of particles by using 3D-hydrodynamic focusing based on SLE fabrication capabilities. Lab Chip 2016; 16(5): 820–828, https://doi.org/10.1039/c5lc01478f.
45. Chung S.H., Cerussi A.E., Klifa C., Baek H.M., Birgul O., Gulsen G., Merritt S.I., Hsiang D., Tromberg B.J. In vivo water state measurements in breast cancer using broadband diffuse optical spectroscopy. Phys Med Biol 2008; 53(23): 6713–6727, https://doi.org/10.1088/0031-9155/53/23/005.
46. Davydov D.A., Budylin G.S., Baev A.V., Vaypan D.V., Seredenina E.M., Matskeplishvili S.T., Evlashin S.A., Kamalov A.A., Shirshin E.A. Monitoring the skin structure during edema in vivo with spatially resolved diffuse reflectance spectroscopy. J Biomed Opt 2023; 28(5): 057002, https://doi.org/10.1117/1.JBO.28.5.057002.
47. Nachabé R., Hendriks B.H., Desjardins A.E., van der Voort M., van der Mark M.B., Sterenborg H.J. Estimation of lipid and water concentrations in scattering media with diffuse optical spectroscopy from 900 to 1,600 nm. J Biomed Opt 2010; 15(3): 037015, https://doi.org/10.1117/1.3454392.
48. Pifferi A., Taroni P., Torricelli A., Messina F., Cubeddu R., Danesini G. Four-wavelength time-resolved optical mammography in the 680–980-nm range. Opt Lett 2003; 28(13): 1138–1140, https://doi.org/10.1364/ol.28.001138.
49. Absorption spectrum of melanin. URL: https://www.cl.cam.ac.uk/~jgd1000/melanin.html.
50. Zonios G., Dimou A., Bassukas I., Galaris D., Tsolakidis A., Kaxiras E. Melanin absorption spectroscopy: new method for noninvasive skin investigation and melanoma detection. J Biomed Opt 2008; 13(1): 014017, https://doi.org/10.1117/1.2844710.
51. Marchesini R., Bono A., Carrara M. In vivo characterization of melanin in melanocytic lesions: spectroscopic study on 1671 pigmented skin lesions. J Biomed Opt 2009; 14(1): 014027, https://doi.org/10.1117/1.3080140.
52. Lim L., Nichols B., Migden M.R., Rajaram N., Reichenberg J.S., Markey M.K., Ross M.I., Tunnell J.W. Clinical study of noninvasive in vivo melanoma and nonmelanoma skin cancers using multimodal spectral diagnosis. J Biomed Opt 2014; 19(11): 117003, https://doi.org/10.1117/1.JBO.19.11.117003.
53. Bilirubin. URL: https://omlc.org/spectra/PhotochemCAD/html/119.html.
54. Doumas B.T., Wu T.W., Jendrzejczak B. Delta bilirubin: absorption spectra, molar absorptivity, and reactivity in the diazo reaction. Clin Chem 1987; 33(6): 769–774.
55. Banerjee A., Bhattacharyya N., Ghosh R., Singh S., Adhikari A., Mondal S., Roy L., Bajaj A., Ghosh N., Bhushan A., Goswami M., Ahmed A.S.A., Moussa Z., Mondal P., Mukhopadhyay S., Bhattacharyya D., Chattopadhyay A., Ahmed S.A., Mallick A.K., Pal S.K. Non-invasive estimation of hemoglobin, bilirubin and oxygen saturation of neonates simultaneously using whole optical spectrum analysis at point of care. Sci Rep 2023; 13(1): 2370, https://doi.org/10.1038/s41598-023-29041-w.
56. Cruz-Landeira A., Bal M.J., Quintela O., López-Rivadulla M. Determination of methemoglobin and total hemoglobin in toxicological studies by derivative spectrophotometry. J Anal Toxicol 2002; 26(2): 67–72, https://doi.org/10.1093/jat/26.2.67.
57. Sekar S.K., Bargigia I., Mora A.D., Taroni P., Ruggeri A., Tosi A., Pifferi A., Farina A. Diffuse optical characterization of collagen absorption from 500 to 1700 nm. J Biomed Opt 2017; 22(1): 15006, https://doi.org/10.1117/1.JBO.22.1.015006.
58. Nazarov D.A., Denisenko G.M., Budylin G.S., Kozlova E.A., Lipina M.M., Lazarev V.A., Shirshin E.A., Tarabrin M.K. Diffuse reflectance spectroscopy of the cartilage tissue in the fourth optical window. Biomed Opt Express 2023; 14(4): 1509–1521, https://doi.org/10.1364/BOE.483135.
59. Taroni P., Quarto G., Pifferi A., Ieva F., Paganoni A.M., Abbate F., Balestreri N., Menna S., Cassano E., Cubeddu R. Optical identification of subjects at high risk for developing breast cancer. J Biomed Opt 2013; 18(6): 060507, https://doi.org/10.1117/1.JBO.18.6.060507.
60. Martínez-Mancera F., Hernandez-Lopez J. In vitro observation of direct electron transfer of human haemoglobin molecules on glass/tin-doped indium oxide electrodes. J Mex Chem Soc 2015; 59(4), https://doi.org/10.29356/jmcs.v59i4.87.
61. Amenhotep Z.D. Hematology and coagulation. In: Self-assessment Q and A in clinical laboratory science, III. Elsevier; 2021; p. 295–313, https://doi.org/10.1016/b978-0-12-822093-1.00025-9.
62. Mentzer W.C., Glader B.E. Erythrocyte disorders in infancy. In: Taeusch H.W., Ballard R.A., Gleason C.A. (editors). Avery’s diseases of the newborn. W.B. Saunders; 2005; р. 1180–1214, https://doi.org/10.1016/B978-072169347-7.50079-2.
63. Vasudevan S., Campbell C., Liu F., O’Sullivan T.D. Broadband diffuse optical spectroscopy of absolute methemoglobin concentration can distinguish benign and malignant breast lesions. J Biomed Opt 2021; 26(6): 065004, https://doi.org/10.1117/1.JBO.26.6.065004.
64. Barham P., Skibsted L.H., Bredie W.L., Frøst M.B., Møller P., Risbo J., Snitkjaer P., Mortensen L.M. Molecular gastronomy: a new emerging scientific discipline. Chem Rev 2010; 110(4): 2313–2365, https://doi.org/10.1021/cr900105w.
65. Arakaki L.S., Schenkman K.A., Ciesielski W.A., Shaver J.M. Muscle oxygenation measurement in humans by noninvasive optical spectroscopy and locally weighted regression. Anal Chim Acta 2013; 785: 27–33, https://doi.org/10.1016/j.aca.2013.05.003.
66. Wang L., Santos E., Schenk D., Rabago-Smith M. Kinetics and mechanistic studies on the reaction between cytochrome c and tea catechins. Antioxidants (Basel) 2014; 3(3): 559–568, https://doi.org/10.3390/antiox3030559.
67. Arai A.E., Kasserra C.E., Territo P.R., Gandjbakhche A.H., Balaban R.S. Myocardial oxygenation in vivo: optical spectroscopy of cytoplasmic myoglobin and mitochondrial cytochromes. Am J Physiol 1999; 277(2): H683–H697, https://doi.org/10.1152/ajpheart.1999.277.2.H683.
68. Bhattacharya M., Dutta A. Computational modeling of the photon transport, tissue heating, and cytochrome c oxidase absorption during transcranial near-infrared stimulation. Brain Sci 2019; 9(8): 179, https://doi.org/10.3390/brainsci9080179.
69. Lindbergh T., Häggblad E., Ahn H., Göran Salerud E., Larsson M., Strömberg T. Improved model for myocardial diffuse reflectance spectra by including mitochondrial cytochrome aa3, methemoglobin, and inhomogenously distributed RBC. J Biophotonics 2011; 4(4): 268–276, https://doi.org/10.1002/jbio.201000048.
70. Lee J., Kim J.G., Mahon S.B., Mukai D., Yoon D., Boss G.R., Patterson S.E., Rockwood G., Isom G., Brenner M. Noninvasive optical cytochrome c oxidase redox state measurements using diffuse optical spectroscopy. J Biomed Opt 2014; 19(5): 055001, https://doi.org/10.1117/1.JBO.19.5.055001.
71. Cerussi A., Shah N., Hsiang D., Durkin A., Butler J., Tromberg B.J. In vivo absorption, scattering, and physiologic properties of 58 malignant breast tumors determined by broadband diffuse optical spectroscopy. J Biomed Opt 2006; 11(4): 044005, https://doi.org/10.1117/1.2337546.
72. Khan M.I.H., Karim M.A. Cellular water distribution, transport, and its investigation methods for plant-based food material. Food Res Int 2017; 99(Pt 1): 1–14, https://doi.org/10.1016/j.foodres.2017.06.037.
73. Yang C.C., Yen Y.Y., Hsu C.K., Cheng N.Y., Tzeng S.Y., Chou S.J., Chang J.M., Tseng S.H. Investigation of water bonding status of normal and psoriatic skin in vivo using diffuse reflectance spectroscopy. Sci Rep 2021; 11(1): 8901, https://doi.org/10.1038/s41598-021-88530-y.
74. Akter S., Hossain Md.G., Nishidate I., Hazama H., Awazu K. Medical applications of reflectance spectroscopy in the diffusive and sub-diffusive regimes. J Infrared Spectrosc 2018; 26(6): 337–350, https://doi.org/10.1177/0967033518806637.
75. Beauvoit B., Evans S.M., Jenkins T.W., Miller E.E., Chance B. Correlation between the light scattering and the mitochondrial content of normal tissues and transplantable rodent tumors. Anal Biochem 1995; 226(1): 167–174, https://doi.org/10.1006/abio.1995.1205.
76. Wilson J.D., Cottrell W.J., Foster T.H. Index-of-refraction-dependent subcellular light scattering observed with organelle-specific dyes. J Biomed Opt 2007; 12(1): 014010, https://doi.org/10.1117/1.2437765.
77. Blaney G., Bottoni M., Sassaroli A., Fernandez C., Fantini S. Broadband diffuse optical spectroscopy of two-layered scattering media containing oxyhemoglobin, deoxyhemoglobin, water, and lipids. J Innov Opt Health Sci 2022; 15(3): 2250020, https://doi.org/10.1142/s1793545822500201.
78. Lam J.H., Tu K.J., Kim S. Narrowband diffuse reflectance spectroscopy in the 900–1000 nm wavelength region to quantify water and lipid content of turbid media. Biomed Opt Express 2021; 12(6): 3091–3102, https://doi.org/10.1364/BOE.425451.
79. Bhagavan N.V. Protein and amino acid metabolism. In: Medical biochemistry. Academic Press; 2002; p. 331–363, https://doi.org/10.1016/b978-012095440-7/50019-6.
80. Maranduca M.A., Branisteanu D., Serban D.N., Branisteanu D.C., Stoleriu G., Manolache N., Serban I.L. Synthesis and physiological implications of melanic pigments. Oncol Lett 2019; 17(5): 4183–4187, https://doi.org/10.3892/ol.2019.10071.
81. Kalia S., Zhao J., Zeng H., McLean D., Kollias N., Lui H. Melanin quantification by in vitro and in vivo analysis of near-infrared fluorescence. Pigment Cell Melanoma Res 2018; 31(1): 31–38, https://doi.org/10.1111/pcmr.12624.
82. Gell D.A. Structure and function of haemoglobins. Blood Cells Mol Dis 2018; 70: 13–42, https://doi.org/10.1016/j.bcmd.2017.10.006.
83. Chan E.D., Chan M.M., Chan M.M. Pulse oximetry: understanding its basic principles facilitates appreciation of its limitations. Respir Med 2013; 107(6): 789–799, https://doi.org/10.1016/j.rmed.2013.02.004.
84. Orlova A.G., Kirillin M.Y., Volovetsky A.B., Shilyagina N.Y., Sergeeva E.A., Golubiatnikov G.Y., Turchin I.V. Diffuse optical spectroscopy monitoring of oxygen state and hemoglobin concentration during SKBR-3 tumor model growth. Laser Phys Lett 2016; 14: 015601, https://doi.org/10.1088/1612-202X/AA4FC1.
85. Diaz P.M., Jenkins S.V., Alhallak K., Semeniak D., Griffin R.J., Dings R.P.M., Rajaram N. Quantitative diffuse reflectance spectroscopy of short-term changes in tumor oxygenation after radiation in a matched model of radiation resistance. Biomed Opt Express 2018; 9(8): 3794–3804, https://doi.org/10.1364/BOE.9.003794.
86. Cochran J.M., Busch D.R., Leproux A., Zhang Z., O’Sullivan T.D., Cerussi A.E., Carpenter P.M., Mehta R.S., Roblyer D., Yang W., Paulsen K.D., Pogue B., Jiang S., Kaufman P.A., Chung S.H., Schnall M., Snyder B.S., Hylton N., Carp S.A., Isakoff S.J., Mankoff D., Tromberg B.J., Yodh A.G. Tissue oxygen saturation predicts response to breast cancer neoadjuvant chemotherapy within 10 days of treatment. J Biomed Opt 2018; 24(2): 1–11, https://doi.org/10.1117/1.JBO.24.2.021202.
87. Brown J.M., Wilson W.R. Exploiting tumour hypoxia in cancer treatment. Nat Rev Cancer 2004; 4(6): 437–447, https://doi.org/10.1038/nrc1367.
88. Khatun F., Aizu Y., Nishidate I. Transcutaneous monitoring of hemoglobin derivatives during methemoglobinemia in rats using spectral diffuse reflectance. J Biomed Opt 2021; 26(3): 033708, https://doi.org/10.1117/1.JBO.26.3.033708.
89. Arakaki L.S., Burns D.H., Kushmerick M.J. Accurate myoglobin oxygen saturation by optical spectroscopy measured in blood-perfused rat muscle. Appl Spectrosc 2007; 61(9): 978–985, https://doi.org/10.1366/000370207781745928.
90. Baranoski G.V., Chen T.F., Kimmel B.W., Miranda E., Yim D. On the noninvasive optical monitoring and differentiation of methemoglobinemia and sulfhemoglobinemia. J Biomed Opt 2012; 17(9): 97005, https://doi.org/10.1117/1.JBO.17.9.097005.
91. Niemann M.J., Sørensen H., Siebenmann C., Lundby C., Secher N.H. Carbon monoxide reduces near-infrared spectroscopy determined ‘total’ hemoglobin: a human volunteer study. Scand J Clin Lab Invest 2017; 77(4): 259–262, https://doi.org/10.1080/00365513.2017.1299209.
92. Allred E.N., Bleecker E.R., Chaitman B.R., Dahms T.E., Gottlieb S.O., Hackney J.D., Pagano M., Selvester R.H., Walden S.M., Warren J. Short-term effects of carbon monoxide exposure on the exercise performance of subjects with coronary artery disease. N Engl J Med 1989; 321(21): 1426–1432. Corrected and republished from: N Engl J Med 1990; 322(14): 1019, https://doi.org/10.1056/NEJM198911233212102.
93. Dervieux E., Bodinier Q., Uhring W., Théron M. Measuring hemoglobin spectra: searching for carbamino-hemoglobin. J Biomed Opt 2020; 25(10): 105001, https://doi.org/10.1117/1.JBO.25.10.105001.
94. Da-Silva S.S., Sajan I.S., Underwood J.P. 3rd. Congenital methemoglobinemia: a rare cause of cyanosis in the newborn — a case report. Pediatrics 2003; 112(2): e158–e161, https://doi.org/10.1542/peds.112.2.e158.
95. Lee J., El-Abaddi N., Duke A., Cerussi A.E., Brenner M., Tromberg B.J. Noninvasive in vivo monitoring of methemoglobin formation and reduction with broadband diffuse optical spectroscopy. J Appl Physiol (1985) 2006; 100(2): 615–622, https://doi.org/10.1152/japplphysiol.00424.2004.
96. Parvez M.A., Yashiro K., Tsunoi Y., Saitoh D., Sato S., Nishidate I. In vivo monitoring of hemoglobin derivatives in a rat thermal injury model using spectral diffuse reflectance imaging. Burns 2024; 50(1): 167–177, https://doi.org/10.1016/j.burns.2023.07.006.
97. Wilson M.T., Reeder B.J. Myoglobin. In: Encyclopedia of respiratory medicine. Academic Press; 2006; p. 73–76, https://doi.org/10.1016/B0-12-370879-6/00250-7.
98. Lin L., Yao J., Li L., Wang L.V. In vivo photoacoustic tomography of myoglobin oxygen saturation. J Biomed Opt 2016; 21(6): 61002, https://doi.org/10.1117/1.JBO.21.6.061002.
99. Denzer M.L., Piao D., Pfeiffer M., Mafi G., Ramanathan R. Novel needle-probe single-fiber reflectance spectroscopy to quantify sub-surface myoglobin forms in beef psoas major steaks during retail display. Meat Sci 2024; 210: 109439, https://doi.org/10.1016/j.meatsci.2024.109439.
100. Gemoliticheskaya bolezn’ ploda i novorozhdennogo: diagnostika, lechenie, profilaktika [Hemolytic disease of the fetus and newborn: diagnostics, treatment, prevention]. Pod red. Volodina N.N. [Volodin N.N. (editor)]. Moscow; 2021.
101. Groenendaal F., van der Grond J., de Vries L.S. Cerebral metabolism in severe neonatal hyperbilirubinemia. Pediatrics 2004; 114(1): 291–294, https://doi.org/10.1542/peds.114.1.291.
102. Rubaltelli F.F., Gourley G.R., Loskamp N., Modi N., Roth-Kleiner M., Sender A., Vert P. Transcutaneous bilirubin measurement: a multicenter evaluation of a new device. Pediatrics 2001; 107(6): 1264–1271, https://doi.org/10.1542/peds.107.6.1264.
103. Gibson A.P., Hebden J.C., Arridge S.R. Recent advances in diffuse optical imaging. Phys Med Biol 2005; 50(4): R1–R43, https://doi.org/10.1088/0031-9155/50/4/r01.
104. Bale G., Elwell C.E., Tachtsidis I. From Jöbsis to the present day: a review of clinical near-infrared spectroscopy measurements of cerebral cytochrome-c-oxidase. J Biomed Opt 2016; 21(9): 091307, https://doi.org/10.1117/1.JBO.21.9.091307.
105. Michel H., Behr J., Harrenga A., Kannt A. Cytochrome c oxidase: structure and spectroscopy. Annu Rev Biophys Biomol Struct 1998; 27: 329–356, https://doi.org/10.1146/annurev.biophys.27.1.329.
106. Tisdall M.M., Tachtsidis I., Leung T.S., Elwell C.E., Smith M. Increase in cerebral aerobic metabolism by normobaric hyperoxia after traumatic brain injury. J Neurosurg 2008; 109(3): 424–432, https://doi.org/10.3171/JNS/2008/109/9/0424.
107. Shin’oka T., Nollert G., Shum-Tim D., du Plessis A., Jonas R.A. Utility of near-infrared spectroscopic measurements during deep hypothermic circulatory arrest. Ann Thorac Surg 2000; 69(2): 578–583, https://doi.org/10.1016/s0003-4975(99)01322-3.
108. Yamada T., Takakura H., Jue T., Hashimoto T., Ishizawa R., Furuichi Y., Kato Y., Iwanaka N., Masuda K. Myoglobin and the regulation of mitochondrial respiratory chain complex IV. J Physiol 2016; 594(2): 483–495, https://doi.org/10.1113/JP270824.
109. Arakaki L.S., Ciesielski W.A., Thackray B.D., Feigl E.O., Schenkman K.A. Simultaneous optical spectroscopic measurement of hemoglobin and myoglobin saturations and cytochrome aa3 oxidation in vivo. Appl Spectrosc 2010; 64(9): 973–979, https://doi.org/10.1366/000370210792434387.

Bylinskaya K.A., Perekatova V.V., Turchin I.V. Study of Minor Chromophores in Biological Tissues by Diffuse Optical Spectroscopy (Review). Sovremennye tehnologii v medicine 2025; 17(1): 146, https://doi.org/10.17691/stm2025.17.1.12