Air drying technique

Figure 3a. The y-globulin adsorbed on the sintered Teflon sample of Figure 2a (air-dry technique). Bovine Cohn II, lOOmg/dL, partial gold decoration. Key ...

Figure 6. Albumin, 2500 mg/dL solution adsorbed on sintered Teflon (air-dry technique). Key a, PGDTEM and by high incidence angle SEM. Bar equals...

Geber, G and Schweizer, D. (1988) Cytochemical heterochromatin differentiation in Sinapis alba (Cruciferae) using a simple air-drying technique for producing chromosome spreads. Plant Syst. Evol. 158,97-106. 

Evans et al. 4) developed an air-drying technique for meiotic preparations from mammalian testes which avoids certain shortcomings of the squash technique, since it provides a large number of analyzable cells and allows the scoring of many cells per animal and per testis. Since the spermatocyte population from a single testis is thoroughly mixed, the samples of cells scored can be considered random and representative of the whole testis. Furthermore, as pointed out by Evans et the... 

R. H. Rothfels and L. Siminovitch, An air-drying technique for flattening chromosomes in mammalian cells grown in vitro. Stain Technol. 33, 73-77 (1958). 

Films or membranes of silkworm silk have been produced by air-drying aqueous solutions prepared from the concentrated salts, followed by dialysis (11,28). The films, which are water soluble, generally contain silk in the silk I conformation with a significant content of random coil. Many different treatments have been used to modify these films to decrease their water solubiUty by converting silk I to silk II in a process found usehil for enzyme entrapment (28). Silk membranes have also been cast from fibroin solutions and characterized for permeation properties. Oxygen and water vapor transmission rates were dependent on the exposure conditions to methanol to faciUtate the conversion to silk II (29). Thin monolayer films have been formed from solubilized silkworm silk using Langmuir techniques to faciUtate stmctural characterization of the protein (30). ResolubiLized silkworm cocoon silk has been spun into fibers (31), as have recombinant silkworm silks (32). 

Technique of thin-layer chromatography. Preparation of the plate. In thin-layer chromatography a variety of coating materials is available, but silica gel is most frequently used. A slurry of the adsorbent (silica gel, cellulose powder, etc.) is spread uniformly over the plate by means of one of the commercial forms of spreader, the recommended thickness of adsorbent layer being 150-250 m. After air-drying overnight, or oven-drying at 80-90 °C for about 30 minutes, it is ready for use. 

One of the most widely used spray-drying techniques for coffee extract involves spraying percolated coffee extract at 40°F into the top of a baffled tower of hot air at 480°F initially. The cooler wet air is removed toward the bottom of the tower and finally a powder of the coffee extract solids leaves the tower at about 90°F. These solids are in the form of hollow beads and contain 3% moisture. 

Grain legumes have also been processed into refined starch (10,11) and protein isolates (12,13,14) by procedures derived from the traditional corn starch and soybean protein industries (15). However, comparative data on product yields, composition and losses have not been published. A commercial plant for the wet processing of field pea into refined starch, protein isolate and refined fiber has been established in Western Canada. Little is known about the characteristics of the protein isolate or refined fiber product. Water-washed starch prepared from the air-classified starch fractions of field pea (16,17) and fababean (6) have been investigated for certain physico-chemical and pasting properties. Reichert (18) isolated the cell wall material from soaked field pea cotyledons and determined its fiber composition and water absorption capacity. In addition, the effects of drying techniques on the characteristics of pea protein Isolates have been determined (14). 

The spotted TLC plates, after evaporation of the sample solvent, is placed in a closed chamber saturated with vapours of the developing solvent(s). One end of the plate is then wetted with the developer by means of either ascending-technique or the descending-technique as shown in Figure 28.2 (a), (b). After the developer has traversed one-half to two-thirds the total length of the TLC plate, the latter is removed from the chamber, air-dried and the positions of the components are located by any of several methods. 

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