Photographic Polaroid

Figure 1. Analytical isoelectric focusing of cellulases from Trichodtrma ree-sei. Detection of CBH I and EG I activities using MeUmbLac, in the absence (A) and presence (B) of 10 mM cellobiose. Lane 1, EG I lane 2, EG I (iso-components) lane 3, CBH I (pi 3.9 component) lane 4, EG I-CBH I mixture). Gels were flooded with the fluorogenic substrate (pH 5.0) and after 5-10 min (room temperature) photographed (Polaroid 57, green filter) on a long wavelength UV-transilluminator (8).

Preliminary X-ray photographs (polaroid film or electronic area detector). 

Fig. 23. An example of fundus (retinal) photography, widely used for diagnosis in opthamology. The photograph is on Polaroid Type 779, a professional...

Fig. 24. A thin layer chromatography (TLC) image, documenting detection of impurities in a series of dye intermediate samples under near-UV illuinination. Columns 1 and 7 represent reference materials. Photographed with Polaroid Type 339 film in a CU-5 closeup camera.

Table 28 Setting eonditions for a Polaroid Land CU 5 eamera with supplementary lens (0.5 dioptres) for photographing TLC plates of 20 x 20 cm format on Type 669 Polaroid color film.

The stopped-flow method generates ordinary kinetic data, presenting values of the property Y, as a function of time. At one time, values were read from a Polaroid photograph of the oscilloscope, but nowadays computer acquisition, presentation, and... 

Medicological purposes. Polaroid photographs are recommended for this purpose. 

X-ray film or the strips were placed in the mask of the camera luminometer loaded with the high-speed Polaroid film. After the strips were exposed to the photographic material for 10-15 min, the film was pulled from the film holder and after 45 s (processing time) the film backing was removed to reveal the developed image. 

Suppose that you are using a Polaroid camera outdoors during the winter. You want your photographs to develop faster. Suggest a way... 

Without a doubt the best known of the instant colour photographic processes is that invented and developed by the Polaroid Corporation. " The original Polacolor system led to the famous Polaroid SX-70 system in 1972. This is a dye diffusion system involving a dye developer in a tripack negative arrangement, placed on top of a receiver sheet, as shown in Figure 2.30. 

Instant photography (e.g. of the Polaroid type) also relies indirectly on the silver halide process but here the reduced Ag (metallic silver) acts as a reducing agent to modify the solubility properties of a dye. The dye is linked covalently to a molecule such as a quinone (Figure 6.5), which is insoluble in water. When this is reduced to hydroquinone, it becomes soluble in alkaline solutions. The principle of this photographic process is the following ... 

As an alternative to drying, gels may be photographed with a Polaroid or digital camera. Illumination should be provided by placing the gel on a light box. Gels may also be scanned with a transparency scanner. 

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