메뉴 건너뛰기




Volumn 212, Issue 1, 2003, Pages 44-52

Of plants and other pets: Practical aspects of freeze-substitution and resin embedding

Author keywords

Cryofixation; Extraction artefacts; HepG2; High pressure freezing; Higher plants; Mini review; Pollen; Specimen preparation; Transmission electron microscopy

Indexed keywords

ACETONE; CELL CULTURE; CELLS; FREEZING; HIGH RESOLUTION TRANSMISSION ELECTRON MICROSCOPY; HISTOLOGY; MAMMALS; PLANTS (BOTANY); RESINS; TISSUE;

EID: 0142088982     PISSN: 00222720     EISSN: None     Source Type: Journal    
DOI: 10.1046/j.1365-2818.2003.01237.x     Document Type: Conference Paper
Times cited : (33)

References (52)
  • 2
    • 0024618976 scopus 로고
    • Extraction of carbon 14-labeled compounds from plant tissue during processing for electron microscopy
    • Coetzee, J. & van der Merwe, C.F. (1989) Extraction of carbon 14-labeled compounds from plant tissue during processing for electron microscopy. J. Electron Microsc. 11, 155-160.
    • (1989) J. Electron Microsc. , vol.11 , pp. 155-160
    • Coetzee, J.1    Van Der Merwe, C.F.2
  • 4
    • 0032170322 scopus 로고    scopus 로고
    • Immuno-cross-reactivity of CUT-1 and cuticlin epitopes between Ascaris lumbricoides, Caenorhabditis elegans, and Heterorhabditis
    • Favre, R., Cermola, M., Paiva Nunes, C., Hermann, R., Müller, M. & Bazzicalupo, P. (1998) Immuno-cross-reactivity of CUT-1 and cuticlin epitopes between Ascaris lumbricoides, Caenorhabditis elegans, and Heterorhabditis. J. Struct. Biol. 123, 1-7.
    • (1998) J. Struct. Biol. , vol.123 , pp. 1-7
    • Favre, R.1    Cermola, M.2    Paiva Nunes, C.3    Hermann, R.4    Müller, M.5    Bazzicalupo, P.6
  • 5
    • 0025349768 scopus 로고
    • Evaluation of freeze-substitution and conventional embedding protocols for routine electron microscopic processing of eubacteria
    • Graham, L.L. & Beveridge, T.J. (1990) Evaluation of freeze-substitution and conventional embedding protocols for routine electron microscopic processing of eubacteria. J. Bacteriol. 172, 2141-2149.
    • (1990) J. Bacteriol. , vol.172 , pp. 2141-2149
    • Graham, L.L.1    Beveridge, T.J.2
  • 6
    • 0033083372 scopus 로고    scopus 로고
    • A new protocol to prepare dry plant specimens for electron microscopy and immunocytochemistry
    • Grote, M., Reichelt, R. & Wiermann, R. (1999) A new protocol to prepare dry plant specimens for electron microscopy and immunocytochemistry. Micron. 30, 65-70.
    • (1999) Micron. , vol.30 , pp. 65-70
    • Grote, M.1    Reichelt, R.2    Wiermann, R.3
  • 8
    • 78651164594 scopus 로고
    • Electron microscopy after rapid freezing on a metal surface and substitution fixation
    • van Harreveld, A. & Crowell, J. (1964) Electron microscopy after rapid freezing on a metal surface and substitution fixation. Anat. Rec. 149, 381-386.
    • (1964) Anat. Rec. , vol.149 , pp. 381-386
    • Van Harreveld, A.1    Crowell, J.2
  • 9
    • 0025065556 scopus 로고
    • Ultrastructure of human basophil leukocytes studied after spray freezing and freeze-substitution
    • Hastie, R. (1990) Ultrastructure of human basophil leukocytes studied after spray freezing and freeze-substitution. Lab. Invest. 62, 119-130.
    • (1990) Lab. Invest. , vol.62 , pp. 119-130
    • Hastie, R.1
  • 10
    • 0025695213 scopus 로고
    • Spurr-resin affects the ultrastructure of freeze-fixed/ freeze-substituted pollen grains
    • Hess, M.W. (1990) Spurr-resin affects the ultrastructure of freeze-fixed/freeze-substituted pollen grains. Ultramicroscopy, 34, 219-221.
    • (1990) Ultramicroscopy , vol.34 , pp. 219-221
    • Hess, M.W.1
  • 11
    • 0005530790 scopus 로고
    • Cell wall development in freeze-fixed pollen: Intine formation of Ledebouria socialis (Hyacinthaceae)
    • Hess, M.W. (1993) Cell wall development in freeze-fixed pollen: intine formation of Ledebouria socialis (Hyacinthaceae). Planta, 189, 139-149.
    • (1993) Planta , vol.189 , pp. 139-149
    • Hess, M.W.1
  • 12
    • 0029186122 scopus 로고
    • High-pressure freeze fixation reveals novel features during ontogenesis of the vegetative cell in Ledebouria pollen: An ultrastructural and cytochemical study
    • Hess, M.W. (1995) High-pressure freeze fixation reveals novel features during ontogenesis of the vegetative cell in Ledebouria pollen: an ultrastructural and cytochemical study. Biochem. Cell Biol. 73, 1-10.
    • (1995) Biochem. Cell Biol. , vol.73 , pp. 1-10
    • Hess, M.W.1
  • 13
    • 0028251186 scopus 로고
    • Subunits of forming pollen exine and Ubisch bodies in freeze substituted Ledebouria socialis Roth
    • Hess, M.W. & Frosch, A. (1994) Subunits of forming pollen exine and Ubisch bodies in freeze substituted Ledebouria socialis Roth. Protoplasma, 182, 10-14.
    • (1994) Protoplasma , vol.182 , pp. 10-14
    • Hess, M.W.1    Frosch, A.2
  • 14
    • 0027966572 scopus 로고
    • Ultrastructural observations on anther tapetum development of freeze-fixed Ledebouria socialis Roth (Hyacinthaceae)
    • Hess, M.W. & Hesse, M. (1994) Ultrastructural observations on anther tapetum development of freeze-fixed Ledebouria socialis Roth (Hyacinthaceae). Planta, 192, 421-430.
    • (1994) Planta , vol.192 , pp. 421-430
    • Hess, M.W.1    Hesse, M.2
  • 15
    • 0028787509 scopus 로고
    • Immunocytochemical localisation of actin and profilin in the generative cell of angiosperm pollen: TEM studies on high-pressure frozen and freeze-substituted Ledebouria socialis Roth (Hyacinthaceae)
    • Hess, M.W., Mittermann, M., Luschnig, C. & Valenta, R. (1995) Immunocytochemical localisation of actin and profilin in the generative cell of angiosperm pollen: TEM studies on high-pressure frozen and freeze-substituted Ledebouria socialis Roth (Hyacinthaceae). Histochem. Cell Biol. 104, 443-451.
    • (1995) Histochem. Cell Biol. , vol.104 , pp. 443-451
    • Hess, M.W.1    Mittermann, M.2    Luschnig, C.3    Valenta, R.4
  • 16
    • 0343526767 scopus 로고    scopus 로고
    • Cryopreparation provides new insight into the effects of Brefeldin a on the structure of the HepG2 Golgi apparatus
    • Hess, M.W., Müller, M., Debbage, PL., Vetterlein, M. & Pavelka, M. (2000) Cryopreparation provides new insight into the effects of Brefeldin A on the structure of the HepG2 Golgi apparatus. J. Struct. Biol. 130, 63-72.
    • (2000) J. Struct. Biol. , vol.130 , pp. 63-72
    • Hess, M.W.1    Müller, M.2    Debbage, P.L.3    Vetterlein, M.4    Pavelka, M.5
  • 17
    • 0030771772 scopus 로고    scopus 로고
    • Profilin revealed in pollen nuclei: Immune-electron microscopy of high-pressure frozen Ledebouria socialis Roth (Hyacinthaceae)
    • Hess, M.W. & Valenta, R. (1997) Profilin revealed in pollen nuclei: immune-electron microscopy of high-pressure frozen Ledebouria socialis Roth (Hyacinthaceae). Sex. Plant Reprod. 10, 283-287.
    • (1997) Sex. Plant Reprod. , vol.10 , pp. 283-287
    • Hess, M.W.1    Valenta, R.2
  • 18
    • 0001085510 scopus 로고
    • In situ localization of a foreign protein in transgenic plants by immunoelectron microscopy following high pressure freezing. Freeze substitution and low temperature embedding
    • Hippe, S., Düring, K. & Kreuzaler, F. (1989) In situ localization of a foreign protein in transgenic plants by immunoelectron microscopy following high pressure freezing. Freeze substitution and low temperature embedding. Eur J. Cell Biol. 50, 230-234.
    • (1989) Eur J. Cell Biol. , vol.50 , pp. 230-234
    • Hippe, S.1    Düring, K.2    Kreuzaler, F.3
  • 19
    • 0027414416 scopus 로고
    • Impact of freeze-substitution on biological electron microscopy
    • Hippe-Sanwald, S. (1993) Impact of freeze-substitution on biological electron microscopy. Microsc. Res. Techn. 24, 400-422.
    • (1993) Microsc. Res. Techn. , vol.24 , pp. 400-422
    • Hippe-Sanwald, S.1
  • 20
    • 0002451141 scopus 로고
    • Preservation of cell ultrastructure by freeze-substitution
    • ed. by K. Mendgen & D.-E. Lesemann, Springer, Berlin
    • Hoch, H.C. (1991) Preservation of cell ultrastructure by freeze-substitution. Electron Microscopy of Plant Pathogens (ed. by K. Mendgen & D.-E. Lesemann), pp. 1-16. Springer, Berlin.
    • (1991) Electron Microscopy of Plant Pathogens , pp. 1-16
    • Hoch, H.C.1
  • 21
    • 0026323790 scopus 로고
    • Freeze substitution reveals a new model for sporangial cleavage in Phytophthora, a result with implications for cytokinesis in other eukaryotes
    • Hyde, G.J., Lancelle. S., Hepler, P.K. & Hardham, A.R. (1991) Freeze substitution reveals a new model for sporangial cleavage in Phytophthora, a result with implications for cytokinesis in other eukaryotes. J. Cell Sci. 100, 735-746.
    • (1991) J. Cell Sci. , vol.100 , pp. 735-746
    • Hyde, G.J.1    Lancelle, S.2    Hepler, P.K.3    Hardham, A.R.4
  • 22
    • 0021742323 scopus 로고
    • The effects of freeze-substitution media on the ultrastructure of inclusion bodies in type II pneumocytes of mouse lung processed by the cryofixation method
    • Ikeda, H., Ichikawa, A. & Ichikawa, M. (1984) The effects of freeze-substitution media on the ultrastructure of inclusion bodies in type II pneumocytes of mouse lung processed by the cryofixation method. J. Electron Microsc. 33, 242-247.
    • (1984) J. Electron Microsc. , vol.33 , pp. 242-247
    • Ikeda, H.1    Ichikawa, A.2    Ichikawa, M.3
  • 23
    • 0031879716 scopus 로고    scopus 로고
    • High-pressure freezing and freeze-substitution of native rat brain: Suitability for preservation and immunoelectron microscopic localization of myelin glycolipids
    • Kirschning, E., Rutter, G. & Hohenberg, H. (1998) High-pressure freezing and freeze-substitution of native rat brain: suitability for preservation and immunoelectron microscopic localization of myelin glycolipids. J. Neurosci. Res. 53, 465-474.
    • (1998) J. Neurosci. Res. , vol.53 , pp. 465-474
    • Kirschning, E.1    Rutter, G.2    Hohenberg, H.3
  • 24
    • 0033594080 scopus 로고    scopus 로고
    • Golgi structure in three dimensions: Functional insights from the normal rat kidney cell
    • Ladinsky, M.S., Mastronarde, D.N., McIntosh, J.R., Howell, K.E. & Staehelin, L.A. (1999) Golgi structure in three dimensions: functional insights from the normal rat kidney cell. J. Cell Biol. 144, 1135-1149.
    • (1999) J. Cell Biol. , vol.144 , pp. 1135-1149
    • Ladinsky, M.S.1    Mastronarde, D.N.2    McIntosh, J.R.3    Howell, K.E.4    Staehelin, L.A.5
  • 25
    • 0000583329 scopus 로고
    • A method for rapid freeze fixation of plant cells
    • Lancelle, S.A., Callaham, D.A. & Hepler, P.K. (1986) A method for rapid freeze fixation of plant cells. Protoplasma, 131, 153-165.
    • (1986) Protoplasma , vol.131 , pp. 153-165
    • Lancelle, S.A.1    Callaham, D.A.2    Hepler, P.K.3
  • 26
    • 0008884712 scopus 로고
    • Immunogold labelling of actin on sections of freeze-substituted plant cells
    • Lancelle, S.A. & Hepler, P.K. (1989) Immunogold labelling of actin on sections of freeze-substituted plant cells. Protoplasma, 150, 72-74.
    • (1989) Protoplasma , vol.150 , pp. 72-74
    • Lancelle, S.A.1    Hepler, P.K.2
  • 27
    • 85167476888 scopus 로고    scopus 로고
    • LEICA Microsystems, Vienna
    • LEICA, (2001) EMAFS Recipe Book. LEICA Microsystems, Vienna.
    • (2001) EMAFS Recipe Book
  • 28
    • 0015112403 scopus 로고
    • Hot alcoholic phosphotungstic acid and uranyl acetate as routine stains for thick and thin sections
    • Locke, M. & Krishnan, N. (1971) Hot alcoholic phosphotungstic acid and uranyl acetate as routine stains for thick and thin sections. J. Cell Biol. 50, 550-557.
    • (1971) J. Cell Biol. , vol.50 , pp. 550-557
    • Locke, M.1    Krishnan, N.2
  • 29
    • 0025729059 scopus 로고
    • The use of freeze-substitution and LR gold in the study of rye grass (Lolium perenne) pollen
    • Martinez, L.B. & Wick, S.M. (1991) The use of freeze-substitution and LR gold in the study of rye grass (Lolium perenne) pollen. J. Electron Microsc. Techn. 18, 305-314.
    • (1991) J. Electron Microsc. Techn. , vol.18 , pp. 305-314
    • Martinez, L.B.1    Wick, S.M.2
  • 30
    • 0022263589 scopus 로고
    • The stabilization of labile configurations of plant cytoplasm by freeze-substitution
    • McCully, M.E. & Canny, M.J. (1985) The stabilization of labile configurations of plant cytoplasm by freeze-substitution. J. Microsc. 139, 27-33.
    • (1985) J. Microsc. , vol.139 , pp. 27-33
    • McCully, M.E.1    Canny, M.J.2
  • 31
    • 0000025569 scopus 로고
    • Vesicle production and fusion during lobe formation in Micrasterias visualized by high pressure freeze fixation
    • Meindl, U., Lancelle, S. & Hepler, P.K. (1992) Vesicle production and fusion during lobe formation in Micrasterias visualized by high pressure freeze fixation. Protoplasma, 170, 104-114.
    • (1992) Protoplasma , vol.170 , pp. 104-114
    • Meindl, U.1    Lancelle, S.2    Hepler, P.K.3
  • 32
    • 76549192504 scopus 로고
    • Plastic embedding mixtures for use in electron microscopy
    • Mollenhauer, H.H. (1964) Plastic embedding mixtures for use in electron microscopy. Stain Technol. 39, 111-114.
    • (1964) Stain Technol. , vol.39 , pp. 111-114
    • Mollenhauer, H.H.1
  • 33
    • 0032412495 scopus 로고    scopus 로고
    • High pressure freezing for immunocytochemistry
    • Monaghan, P., Perusinghe, N. & Müller, M. (1998) High pressure freezing for immunocytochemistry. J. Microsc. 192, 248-258.
    • (1998) J. Microsc. , vol.192 , pp. 248-258
    • Monaghan, P.1    Perusinghe, N.2    Müller, M.3
  • 34
    • 0002133971 scopus 로고
    • Theory and practice of high pressure freezing
    • ed. by R. A. Steinbrecht & K. Zierold, Springer, Berlin
    • Moor, H. (1987) Theory and practice of high pressure freezing. Cryotechniques in Biological Electron Microscopy (ed. by R. A. Steinbrecht & K. Zierold), pp. 17 5 -191. Springer, Berlin.
    • (1987) Cryotechniques in Biological Electron Microscopy , pp. 175-191
    • Moor, H.1
  • 35
    • 0030851075 scopus 로고    scopus 로고
    • A universal post-embedding protocol for immunogold labelling of osmium-fixed, epoxy resin-embedded tissue
    • Morris, R.E. & Ciraolo, G.M. (1997) A universal post-embedding protocol for immunogold labelling of osmium-fixed, epoxy resin-embedded tissue. J. Electron Microsc. 46, 315-319.
    • (1997) J. Electron Microsc. , vol.46 , pp. 315-319
    • Morris, R.E.1    Ciraolo, G.M.2
  • 36
    • 0036239767 scopus 로고    scopus 로고
    • Improved method for visualizing coated pits, microfilaments, and microtubules in cryofixed and freeze-substituted plant cells
    • Murata, T., Karahara, I., Kozuka, T., Giddings, T.H. Jr, Staehelin, L.A. & Mineyuki, Y. (2002) Improved method for visualizing coated pits, microfilaments, and microtubules in cryofixed and freeze-substituted plant cells. J. Electron Microsc. 51, 133-136.
    • (2002) J. Electron Microsc. , vol.51 , pp. 133-136
    • Murata, T.1    Karahara, I.2    Kozuka, T.3    Giddings T.H., Jr.4    Staehelin, L.A.5    Mineyuki, Y.6
  • 38
    • 0025739282 scopus 로고
    • Advantages of fast-freeze fixation followed by freeze-substitution for the preservation of cell integrity
    • Nicolas, G. (1991) Advantages of fast-freeze fixation followed by freeze-substitution for the preservation of cell integrity. J. Electron Microsc. Techn. 18, 395-405.
    • (1991) J. Electron Microsc. Techn. , vol.18 , pp. 395-405
    • Nicolas, G.1
  • 39
    • 0025640095 scopus 로고
    • Structure of pollen grains of Tradescantia reflexa with special reference to the generative cell and the ER around it
    • Noguchi, T. & Ueda, K. (1990) Structure of pollen grains of Tradescantia reflexa with special reference to the generative cell and the ER around it. Cell Structure Function, 15, 379-384.
    • (1990) Cell Structure Function , vol.15 , pp. 379-384
    • Noguchi, T.1    Ueda, K.2
  • 40
    • 0034802410 scopus 로고    scopus 로고
    • Three-dimensional analysis of syncytial-type cell plates during endosperm cellularization visualized by high resolution electron tomography
    • Otegui, M.S., Mastronarde, D.N., Kang, B.-H., Bednarek, S.Y. & Staehelin, L.A. (2001) Three-dimensional analysis of syncytial-type cell plates during endosperm cellularization visualized by high resolution electron tomography. Plant Cell, 13, 2033-2051.
    • (2001) Plant Cell , vol.13 , pp. 2033-2051
    • Otegui, M.S.1    Mastronarde, D.N.2    Kang, B.-H.3    Bednarek, S.Y.4    Staehelin, L.A.5
  • 41
    • 0029148984 scopus 로고
    • Cytokinesis in tobacco BY-2 and root tip cells: A new model of cell plate formation in higher plants
    • Samuels, A.L., Giddings, T.H. Jr & Staehelin, L.A. (1995) Cytokinesis in tobacco BY-2 and root tip cells: a new model of cell plate formation in higher plants. J. Cell Biol. 130, 1345-1357.
    • (1995) J. Cell Biol. , vol.130 , pp. 1345-1357
    • Samuels, A.L.1    Giddings T.H., Jr.2    Staehelin, L.A.3
  • 43
    • 0002933416 scopus 로고
    • Cryofixation without pretreatment at ambient pressure
    • ed. by R. A. Steinbrecht & K. Zierold, Springer, Berlin
    • Sitte, H., Edelmann, L. & Neumann, K. (1987) Cryofixation without pretreatment at ambient pressure. Cryotechniques in Biological Electron Microscopy (ed. by R. A. Steinbrecht & K. Zierold), pp. 87-113. Springer, Berlin.
    • (1987) Cryotechniques in Biological Electron Microscopy , pp. 87-113
    • Sitte, H.1    Edelmann, L.2    Neumann, K.3
  • 44
    • 0014444144 scopus 로고
    • A low-viscosity epoxy resin embedding medium for electron microscopy
    • Spurr, A.R. (1969) A low-viscosity epoxy resin embedding medium for electron microscopy. J. Ultrastruct. Res. 26, 31-43.
    • (1969) J. Ultrastruct. Res. , vol.26 , pp. 31-43
    • Spurr, A.R.1
  • 45
    • 17544384540 scopus 로고    scopus 로고
    • Localisation of allergens in ryegrass pollen and in airborne micronic particles
    • Staff, I.A., Schappi, G. & Taylor, P.E. (1999) Localisation of allergens in ryegrass pollen and in airborne micronic particles. Protoplasma, 208, 47-57.
    • (1999) Protoplasma , vol.208 , pp. 47-57
    • Staff, I.A.1    Schappi, G.2    Taylor, P.E.3
  • 46
    • 0028154250 scopus 로고
    • The proteins encoded by tapetum-specific transcripts Satap35 and Satap44, from Sinapis alba L. are localized in the exine cell wall layer of developing microspores
    • Staiger, D., Kappeler, S., Müller, M. & Apel, K. (1994) The proteins encoded by tapetum-specific transcripts Satap35 and Satap44, from Sinapis alba L. are localized in the exine cell wall layer of developing microspores. Planta, 192, 221-231.
    • (1994) Planta , vol.192 , pp. 221-231
    • Staiger, D.1    Kappeler, S.2    Müller, M.3    Apel, K.4
  • 47
    • 0002743936 scopus 로고
    • Freeze-substitution and freeze-drying
    • ed. by R. A. Steinbrecht & K. Zierold, Springer, Berlin
    • Steinbrecht, R.A. & Müller, M. (1987) Freeze-substitution and freeze-drying. Cryotechniques in Biological Electron Microscopy (ed. by R. A. Steinbrecht & K. Zierold), pp. 149-172. Springer, Berlin.
    • (1987) Cryotechniques in Biological Electron Microscopy , pp. 149-172
    • Steinbrecht, R.A.1    Müller, M.2
  • 48
    • 0024847359 scopus 로고
    • High-pressure freezing comes of age
    • Studer, D., Michel, M. & Müller, M. (1989) High-pressure freezing comes of age. Scanning Microsc. 3 (Suppl.), 253-269.
    • (1989) Scanning Microsc. , vol.3 , Issue.SUPPL. , pp. 253-269
    • Studer, D.1    Michel, M.2    Müller, M.3
  • 49
    • 0028232098 scopus 로고
    • Localization of the two major allergens in rye-grass pollen using specific monoclonal antibodies and quantitative analysis of immunogold labelling
    • Taylor, P.E., Staff, I.A., Singh, M.B. & Knox, R.B. (1994) Localization of the two major allergens in rye-grass pollen using specific monoclonal antibodies and quantitative analysis of immunogold labelling. Histochem. J. 26, 392-401.
    • (1994) Histochem. J. , vol.26 , pp. 392-401
    • Taylor, P.E.1    Staff, I.A.2    Singh, M.B.3    Knox, R.B.4
  • 50
    • 0031936686 scopus 로고    scopus 로고
    • High pressure freezing of plant cells cultured in cellulose microcapillaries
    • Tiedemann, J., Hohenberg, H. & Kollmann, R. (1998) High pressure freezing of plant cells cultured in cellulose microcapillaries. J. Microsc. 189, 163-171.
    • (1998) J. Microsc. , vol.189 , pp. 163-171
    • Tiedemann, J.1    Hohenberg, H.2    Kollmann, R.3
  • 51
    • 0036440834 scopus 로고    scopus 로고
    • Freeze-substitution of high-pressure frozen samples: The visibility of biological membranes is improved when the substitution medium contains water
    • Walther, P. & Ziegler, A. (2002) Freeze-substitution of high-pressure frozen samples: the visibility of biological membranes is improved when the substitution medium contains water. J. Microsc. 208, 3-10.
    • (2002) J. Microsc. , vol.208 , pp. 3-10
    • Walther, P.1    Ziegler, A.2
  • 52
    • 0035141877 scopus 로고    scopus 로고
    • Nodal endoplasmatic reticulum, a specialised form of endoplasmatic reticulum found in gravity-sensing root tip columella cells
    • Zheng, H.Q. & Staehelin, L.A. (2001) Nodal endoplasmatic reticulum, a specialised form of endoplasmatic reticulum found in gravity-sensing root tip columella cells. Plant Physiol. 125, 252-265.
    • (2001) Plant Physiol. , vol.125 , pp. 252-265
    • Zheng, H.Q.1    Staehelin, L.A.2


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.