RESUMEN
The relative DNA content of Feulgen stained nuclei, or concentrations of stoichiometrically binding dyes can be determined by the television texture analysis system. This determination is based on the measurement of areas at preset integer intervals of transmittance. The method includes an unavoidable error in DNA quantification caused by the smallest preset integer value of transmittance at the densitometer unit. The error at the TAS is calculable by a theoretical reduction of the preset intervals for delta T. The calculation results in a correcting factor of 0 less than or equal to 4.1% of the whole measured area of a nucleus. The revised relative DNA content can now be calculated by D=E.A.1.041.
Asunto(s)
ADN/análisis , Técnicas Citológicas , Humanos , Matemática , Fotometría , Coloración y Etiquetado , TelevisiónRESUMEN
The amount of light energy a particle absorbs does not depend upon correct focus. The change in the path of light rays brought about by defocusing causes absorbing areas to be registered as areas of higher transmittance than when in focus. Already wellknown in photometry, this effect is put to use by the "blind focus" method at the television texture analysis system (TAS, Leitz). Some chromophores within the object to be measured are compared to a preset value of transmittance, for example T = 0.40. Only the area representing the structures as dense or denser than the preset density are registered. If the structures are out of focus the size of the registered area is too low, since by defocusing, structures to be measured become pale and diffuse, the correct focus corresponds to the largest area to a preset value of transmittance.