COLOR TRANSLATING TV ULTRAVIOLET MICROSCOPE 



for studying the topography, chemical simi- 

 larities and dissimilarities, and the absorp- 

 tion spectrum of cellular components, syn- 

 thetic and natural fibers, crystals, and 

 amorphous substances. Its usefulness enters 

 fields of investigation in biology, medicine, 

 physics, and metallurgy as well as organic, 

 inorganic, and physical chemistry. 



Operation. The Model ME- 10 la TV ul- 

 traviolet microscope essentially consists of a 

 triple monochromator system, which se- 

 quentially illuminates a specimen at three 

 easily preselected ultraviolet wavelengths 

 down to 2400A. The microscope proper pro- 

 vides coarse and fine adjustments for the 

 condenser and objective, which consist of 

 53 X apochromatized catadioptric lenses 

 furnished with the microscope. The objec- 

 tive fine focus is in steps of one micron. 

 The specimen sUde rests on a microscope 

 stage, which allows circular and x-y move- 

 ments. The three sequential UV beams 

 are then picked up by the projection eye- 

 piece (3.5 X and 10 X) which projects 

 the absorption images of the specimen on 

 to the three UV-Vidicon tubes of the color 

 television cameras. The JTV wavelength 

 separation is achieved by means of a rotating 

 mirror system. Each vidicon is associated 

 with a primary color in a closed loop color 

 television system. The presence of a specific 

 color in the image on the 15" television 

 monitor screen indicates transmission of the 

 corresponding ultraviolet wavelength. A 

 camera is provided to obtain color photo- 

 graphs of the television monitor screen 

 display. Magnifications from specimen to 

 screen of about 4,000 X to 25,000 X are 

 possible. Resolution, under favorable condi- 

 tions, is of the order of 0.3 micron. Varia- 

 tions in hue correspond to differences in 

 transmission spectra and thus indicate differ- 

 ences in chemical composition. Variations 

 in optical density (with no color difference) 

 indicate various amounts of material of 



the same absorption spectrum in the light 

 path. 



The line analyzing microspectrophotom- 

 eter simultaneously displays the point-to- 

 point absorption variation for any selected 

 ultraviolet wavelength by extracting any 

 one of the horizontal scan hues in the color 

 television monitor for display on the line 

 analyzer 5" screen. A dry processing camera 

 is provided to obtain permanent records of 

 the transmission curves. 



Since specimen illumination for any wave- 

 length is not continuous but occurs in the 

 form of about 14 millisecond long pulses, 

 the problem of irradiation damage to cells 

 is minimized. 



The use of three TV cameras overcomes 

 the serious problem of color carry-over. 



Applications. The microscope is intended 

 for quantitative and qualitative investiga- 

 tions from 2400A to 6000A. To a major ex- 

 tent, investigations to date have been in the 

 medical field in the examination of cells 

 (living, stained, or unstained) for determin- 

 ing chemical similarities and dissimilarities 

 of objects within the specimen as well as 

 the structure and topography of the cell. 

 Microchemical analysis can be performed 

 by this technique. Unstained and living 

 specimens, which are entirely colorless 

 when viewed in visible light, give results 

 comparable to a selectively stained sample. 

 For instance, at 2800A, absorption coincides 

 closely with areas rich in proteins containing 

 amino acids, which would take an acid stain 

 such as eosin; on the other hand, areas 

 which absorb heavily at 2600A often cor- 

 respond to those that take basic stains 

 indicating the presence of nucleic acid. 



Focusing and area selection are performed 

 as in ordinary microscopy except that eye 

 strain is reduced to a minimum since the 

 operator need only watch the color TV 

 screen during these operations. 



G. L. Clark 



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