Schiff s reagent

Gives some of the tests for acetaldehyde, but more feebly e.g., it restores the colour to SchifF s reagent, gives a yellow resin with NaOH, and responds to the nitroprusside test. With ammoniacal AgN03, it gives a silver minor only after 2 -3 minutes warming. It does not give the iodoform reaction. 

Does not restore the pink colour to SchifF s reagent. 

Ferric chloride coloration. Add a few drops of FeClj solution to a few drops of the aldehyde an intense violet coloration is produced, a. Does not restore the colour to Schiff s reagent. 

Schiff s reagent. Add about 1 ml. of SchifTs reagent to about 1 ml. of acetone and note the very slow formation of a magenta colour. Neither acetophenone nor benzophenone reacts in this way. 

Schiff s Reagent. Dissolve 1 g. of rosaniline in 50 ml. of water with gentle warming. Cool, saturate with SO, add about i g. of animal charcoal, shake and filter make up to i litre with water. If the pink colour reappears on standing, add a few drops of SOj-water carefully with stirring until the colour Just disappears. 

Schiff s reagent is a dilute solution of fuchsin hydrochloride (p-rosaniline) that has been decolourised by sulphur dioxide. This decolourisation is the result of a... 

An alternative procedure for the above test is as follows. Mix 2-3 ml. of 2 per cent, aqueous paraperiodic acid solution with 1 drop of dilute sulphuric acid (ca. 2 5N) and add 20-30 mg. of the compound. Shake the mixture for 5 minutes, and then pass sulphur dioxide through the solution until it acquires a pale yellow colour (to remove the excess of periodic acid and also iodic acid formed in the reaction). Add 1-2 ml. of Schiff s reagent (Section 111,70) the production of a violet colour constitutes a positive test. 

In brief, the Feulgen staining procedure consists in (a) fixation of root tips in Camoy s solution I (ethanol and acetic acid, 3 1 v/v) (b) staining with Schiff s reagent and (c) two successive immersions in 95% ethanol and histolemon Erba baths. More details on the procedure can be found in Ferrara et al. (2001). 

Rinse in two changes of absolute ethanol Rinse in dH20 Immerse in Schiff s reagent (see PAS method) for 10-30 min Rinse in dH20... 

Schiff s reagent analy chem An aqueous solution of rosaniline and sulfurous add used in the Schiff test. shifs re,a-(3nt ... 

Schiff s reagent, liquid chromatography, 719 Sclerotium rolfsii, reactive oxygen species, 610 Scopoletin, hydrogen peroxide fluorometry, 627, 642... 

This procedure is not solely specific for carbohydrate side chains of proteins. Unglycosylated proteins may also be stained. To identify glycosylated proteins, the sample should be run in at least two identical lanes cut the gel and stain a lane with the common protein silver stain (Protocols 2.4.2.1 to 2.4.2.4) and the other lane by the described method. Compare pattern and intensity to identify glycoproteins. Glycosylated macromolecules are also stainable with Schiff s reagent (Protocol 2.4.4.1), but with less sensitivity. 

PAS staining (periodic acid - Schiff s reagent) colors compounds with vicinal hydroxyl groups, i.e., mainly oligosaccharide side chains in glycoproteins, glycolipids, and nucleic acids. The sensitivity and stability is much lower than the silver staining Protocol 2.4.2.S but more specific. 

Incubate the gel in the dark with Soln. D for 1 -1.5 h. Remove excess of Schiff s reagent by extensive washes with Soln. E. If the Schiff s reagent is not removed completely, the gel becomes purple during drying. 

Preparation of Schiff s reagent. Method 1. Dissolve 0- 2 g. of pure p-rosaniline hydrochloride in 20 ml. of a cold, freshly-prepared, saturated aqueous solution of sulphur dioxide allow the solution to stand for a few hours until it becomes colourless or pale yellow. Dilute the solution to 200 ml. and keep it in a tightly, stoppered bottle. If the bottle is not adequately stoppered, the reagent will gradually lose sulphur dioxide and the colour will return. The solution keeps well if not unnecessarily exposed to light and air. 

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