The amount of a light-absorbing substance in tissue components can be determined in situ or after extraction by photographic or photoelectric measurement of the absorption. In the case of an extract, spheres (1) or lens-shaped droplets (2) can be used as microcuvettes. With spheres, a determination of the total absorption is straightforward since the volume of the absorbance per unit length can...

We describe how a microcomputer (Apple II Plus) can be interfaced with a commercial densitometer to provide control functions, do automated data processing, and print final reports. The amplified densitometer photodetector signal is digitized, stored, and plotted on the cathode-ray tube to provide a real-time graphical display of data acquisition. The software was designed to identify automatic...

PURPOSE We compared macular pigment (MP) measurements using customized heterochromatic flicker photometry (Macular Metrics Densitometer) and dual-wavelength fundus autofluorescence (Heidelberg Spectralis HRA + OCT MultiColor) in subjects with early age-related macular degeneration (AMD). METHODS Macular pigment was measured in 117 subjects with early AMD (age, 44-88 years) using the Densitome...

Hadamard transform spatial multiplexing techniques are applied to laser densitometry in order to prevent the photo-induced degradation of sensitive materials. Photochemical and thermal degradations can often occur in point focused scanning laser densitometry. In spatial multiplexing, the excitation source is defocused and efficiently distributed throughout the sample, reducing local power densi...

An inexpensive video densitometer based on an Apple II microcomputer using commercially available components was developed. The device was used to quantitate charred lipid and colored spots on thin-layer chromatography plates. The method is useful for lipid samples weighing 0.1 to 4 micrograms on high-performance plates and 1 to 20 micrograms on ordinary plates. The software automatically corre...