Microscopy kev faib tawm thiab cov hauv paus ntsiab lus ua haujlwm rau kev tshawb fawb ntawm tes
Lub tshuab microscope yog lub cuab yeej tseem ceeb rau kev soj ntsuam cov hlwb. Raws li cov teeb pom kev sib txawv, nws tuaj yeem muab faib ua ob pawg: optical microscopes thiab electron microscopes. Cov qub siv lub teeb pom kev zoo (UV microscopes siv lub teeb ultraviolet) ua lub teeb ci, thaum tom kawg siv cov kab hluav taws xob ua lub teeb ci.
-, Optical microscope
(1) Ordinary optical microscope
Ordinary biological microscopes yog tsim los ntawm peb qhov chaw, uas yog: ① illumination system, nrog rau lub teeb ci thiab condenser; ② optical magnification system, tsim los ntawm lub hom phiaj lens thiab eyepiece, uas yog lub cev tseem ceeb ntawm lub tshuab tsom. Txhawm rau txhawm rau tshem tawm cov kev tsis sib haum xeeb thiab chromatic aberration, ob lub qhov muag thiab lub hom phiaj ③Mechanical device, siv los kho cov khoom siv thiab ua kom yooj yim saib (Daim duab 2-1).
Txawm hais tias daim duab ntawm lub tshuab ntsuas pom tseeb tsis yog tsuas yog txiav txim siab los ntawm kev nthuav dav, tab sis kuj tseem cuam tshuam nrog kev daws teeb meem ntawm lub tshuab tsom. Qhov kev daws teeb meem yog hais txog lub peev xwm ntawm lub tshuab tsom iav (los yog tib neeg lub qhov muag kom deb ntawm 25cm ntawm lub hom phiaj) kom paub qhov txawv qhov tsawg tshaj plaws ntawm cov khoom. Qhov loj ntawm qhov kev daws teeb meem yog txiav txim los ntawm Lub wavelength thiab aperture ratio ntawm lub teeb thiab lub refractive index ntawm nruab nrab yog qhia los ntawm cov mis:
Hauv cov mis: n=refractive index ntawm nruab nrab;=aperture lub kaum sab xis (lub kaum sab xis qhib ntawm cov qauv mus rau lub hom phiaj lens aperture), NA=lens aperture (numberic aperture). Lub kaum sab xis yog ib txwm tsawg dua 180 degree, yog li tus nqi siab tshaj plaws ntawm sina / 2 yuav tsum tsawg dua 1.
Lub refractive index ntawm cov iav siv los ua lub lens optical yog 1.65 mus rau 1.78, thiab qhov refractive index ntawm nruab nrab siv yog ze rau lub iav, qhov zoo dua. Rau lub hom phiaj qhuav lo ntsiab muag, qhov nruab nrab yog huab cua, thiab lub lens aperture feem ntau yog 0.05 txog 0.95; rau cov roj lo ntsiab muag, cov roj cedar yog siv los ua qhov nruab nrab, thiab lub lens aperture piv yuav nyob ze rau 1.5.
Lub wavelength ntawm lub teeb zoo tib yam yog {{0}}}nm, yog li qhov kev daws teeb meem ntawm lub tshuab ntsuas qhov ntsuas yuav tsis tsawg dua 0.2μm, thiab qhov kev daws teeb meem ntawm tib neeg lub qhov muag yog 0.2 hli, yog li ntawd Qhov siab tshaj plaws magnification ntawm lub tshuab tsom iav dav dav feem ntau yog 1000X.
(2) Fluorescence microscopy
Qee yam khoom hauv hlwb, xws li chlorophyll, tuaj yeem fluoresce tom qab irradiated los ntawm ultraviolet rays; Qee cov khoom lawv tus kheej tsis tuaj yeem fluoresce, tab sis yog tias lawv stained nrog fluorescent dyes lossis fluorescent antibodies, lawv tuaj yeem fluoresce thaum irradiated los ntawm ultraviolet rays, thiab fluorescence microscope (Fig. 2-2, 3, 4) yog ib qho ntawm cov cuab yeej. rau kev tshawb fawb zoo thiab ntau yam ntawm cov khoom no.
Fluorescence microscopes thiab dog dig microscopes muaj qhov sib txawv hauv qab no:
1. Txoj kev illumination feem ntau yog epi-illumination, uas yog, lub teeb qhov chaw yog projected ntawm tus qauv los ntawm lub hom phiaj lens (Daim duab 2-3);
2. Lub teeb ci yog ultraviolet lub teeb, lub wavelength luv dua, thiab qhov kev daws teeb meem yog siab dua li ntawm cov tshuab microscopes;
3. Muaj ob lub lim dej tshwj xeeb, ib qho nyob rau pem hauv ntej ntawm lub teeb ci yog siv los lim tawm lub teeb pom kev, thiab ib qho nruab nrab ntawm lub qhov muag thiab lub hom phiaj lens yog siv los lim tawm lub teeb ultraviolet los tiv thaiv lub qhov muag.
(3) Laser scanning confocal microscope
Laser confocal scanning microscope (laser confocal scanning microscope, Daim duab 2-5, 6) siv laser li scanning lub teeb qhov chaw, thiab scans imaging point los ntawm taw tes, kab los ntawm kab, nto ntawm nto, thiab lub scanning laser thiab fluorescence sau qhia ib Lub hom phiaj lens, thiab lub hom phiaj ntawm lub hom phiaj lens yog Lub focal point ntawm scanning laser kuj yog cov khoom taw tes ntawm instantaneous imaging. Vim hais tias lub wavelength ntawm lub laser beam yog luv luv thiab lub beam yog heev nyias, lub confocal laser scanning microscope muaj ib tug ntau dua kev daws teeb meem, uas yog hais txog 3 npaug ntawm ib tug dog dig optical microscope. Lub kaw lus yog tsom ib zaug thiab qhov scan tsuas yog siv rau ib lub dav hlau ntawm cov qauv. Thaum lub tsom qhov tob sib txawv, cov duab ntawm qhov sib txawv qhov tob ntawm cov qauv tuaj yeem tau txais. Cov ntaub ntawv duab no khaws cia rau hauv lub computer. Los ntawm kev txheeb xyuas lub computer thiab simulation, peb-seem qauv ntawm cov qauv ntawm tes tuaj yeem tshwm sim.
Confocal laser scanning microscopy tuaj yeem siv tsis tau tsuas yog txhawm rau soj ntsuam cell morphology, tab sis kuj rau kev txheeb xyuas ntau ntawm cov khoom siv hauv lub cev, cov txheeb cais qhov muag pom thiab ntsuas ntawm cov kab mob ntawm tes.
(4) Tsaus teb microscope
Lub tshuab ntsuas qhov tsaus nti (tsaus thaj chaw microscope, Daim duab 2-7) muaj ib daim ntawv lub teeb nyob rau hauv nruab nrab ntawm lub condenser, yog li ntawd lub illumination lub teeb tsis ncaj qha nkag mus rau tib neeg lo ntsiab muag, thiab tsuas yog lub teeb reflected thiab disfracted los ntawm cov qauv. tso cai rau nkag mus rau lub hom phiaj lens, yog li lub keeb kwm yav dhau ntawm qhov kev pom yog xim dub, cov npoo ntawm cov khoom yog ci. Siv lub tshuab microscope no, cov khoom me me li 4-200nm tuaj yeem pom, thiab qhov kev daws teeb meem tuaj yeem siab dua 50 npaug ntawm cov tshuab microscopes.
(5) Phase contrast microscope
Phasecontrast microscope (phasecontrast microscope, Daim duab 2-8, 9) los ntawm P. Zernike tau tsim nyob rau hauv 1932 thiab yeej qhov Nobel nqi zog hauv Physics hauv 1953 rau nws. Qhov loj tshaj plaws ntawm lub tshuab ntsuas no yog tias nws tuaj yeem soj ntsuam cov qauv tsis muaj xim thiab cov hlwb nyob.
Lub hauv paus ntsiab lus ntawm theem contrast microscopy yog hloov txoj kev kho qhov muag qhov sib txawv ntawm lub teeb pom kev dhau los ntawm cov qauv mus rau qhov sib txawv amplitude, yog li txhim kho qhov sib txawv ntawm ntau yam qauv thiab ua rau ntau yam qauv pom meej. Tom qab dhau los ntawm cov qauv, lub teeb yog refracted, deviated los ntawm qhov qub optical txoj kev, thiab ncua los ntawm 1/4λ (wavelength). Ua kom muaj zog, nce lossis txo qhov amplitude, nce qhov sib piv. Nyob rau hauv cov nqe lus ntawm cov qauv, theem contrast microscopes muaj ob yam tshwj xeeb uas txawv los ntawm dog dig optical microscopes:
1. Lub diaphragm yog nyob nruab nrab ntawm lub teeb qhov chaw thiab lub condenser, thiab nws txoj haujlwm yog ua kom lub teeb hla ntawm lub condenser tsim lub teeb hollow lub khob hliav qab thiab tsom rau cov qauv.
2. Phaj phaj (annular phaseplate) ntxiv cov phaj phaj coated nrog magnesium fluoride nyob rau hauv lub hom phiaj lens, uas tuaj yeem ncua sij hawm ntawm lub teeb ncaj qha los yog lub teeb diffraction ntawm 1/4λ. Muaj ob hom:
①A ntxiv rau theem phaj: Lub teeb ncaj qha ncua los ntawm 1/4λ. Tom qab ob pawg ntawm lub teeb tsis sib xyaw ua ke, lub teeb nthwv dej tau ntxiv ua ke, thiab qhov amplitude tau nce ntxiv. Cov qauv ntawm cov qauv yog ci dua li qhov nruab nrab ib puag ncig, tsim qhov sib txawv ci ntsa iab (lossis tsis zoo sib piv).
② B ntxiv theem phaj: Lub teeb pom kev sib txawv yog ncua los ntawm 1/4λ. Tom qab ob txheej ntawm cov duab sib xyaw ua ke, lub teeb tsis muaj qhov sib cais, thiab qhov amplitude ua me me, ua rau qhov sib txawv tsaus nti (los yog qhov zoo sib xws), thiab cov qauv yog tsaus dua li qhov nruab nrab ib puag ncig.
(6) Polarizing microscope
Polarizing microscope yog siv los kuaj cov tshuaj nrog birefringence, xws li filaments, spindles, collagen, chromosomes thiab lwm yam. Qhov sib txawv ntawm cov tshuab microscopes yog tias muaj lub polarizer (polarizer) nyob rau hauv pem hauv ntej ntawm lub teeb ci, kom lub teeb nkag mus rau lub tshuab tsom iav yog lub teeb polarized, thiab muaj cov ntsuas (polarizer uas nws txoj kev taw qhia polarization yog perpendicular rau polarizer) hauv lub lens fwj. Cov theem ntawm lub tshuab ntsuas no tuaj yeem tig tau. Thaum ib leeg-refractive tshuaj raug muab tso rau ntawm theem, txawm li cas los xij lub theem tig, txij li ob lub polarizers yog ntsug, tsis pom lub teeb pom kev hauv lub tshuab, thiab lub teeb tsis pom hauv lub tshuab tsom. Thaum nkag mus rau hauv cov ntaub ntawv birefringent, cov theem tig tuaj yeem pom cov khoom zoo li no vim tias lub teeb yog deflected thaum nws dhau los ntawm cov khoom siv.
