Alizarine red

Colorimetric methods always include hafnium. Most methods employ a separation step such as solvent extraction. The three reagents used successfully are 8-hydroxyquinoline (88), alizarin red S (89), and catechol violet (90). 

Pregnant females were sacrificed by carbon dioxide anesthesia on day 21 of gestation the uterine horns were exteriorized through a midline incision in the abdominal wall, and the number and position of live, dead, and resorbed fetuses were noted. After being weighed and sexed, the fetuses were examined for external anomalies the crown-rump length was measured with a vernier caliper. Half of each litter was preserved in Bouin s solution and later examined for soft tissue anomalies (16) the other half was preserved in alcohol, cleared and stained with Alizarin red-S, and examined for skeletal abnormalities (2). 

Prussia (in northern Germany) was industrializing and urbanizing so quickly that onlookers called it Europe s Wild West. Building on synthetic alizarin red, Germany institutionalized chemical research. Perkin and other English inventors had established companies to exploit a product, but German firms exploited the research process itself. 

The potentiometric method also surpasses the others for speed, simplicity, precision and accuracy as indicated in Table 12.1. Furthermore, it is particularly suited to the continuous monitoring of fluoride levels in drinking water. The spectrophotometric methods are lengthy because of the time required to develop a stable colour (up to 1 hour), the alizarin red-S complex being especially poor in this respect. It was noted, however, that for the three bleaching methods (1-3) the rate of change of absorbance by the blank closely followed that of solutions containing fluoride, i.e. the difference between the blank and a sample absorbance is nearly constant. 

FIGURE 8.6. Effect of litter size (live fetuses per litter) on incidence of supernumerary rib in 1379 control rat litters. Between 1978 and 1988, fetal skeletons from 1379 litters of control rats were stained with alizarin red and examined for supernumerary rib. 

Numerous experimental systems verified the theory of surface electrode reactions. Reductions of methylene blue [92], azobenzene [79, 82] alizarine red S [93], probucol [94], molybdenum(V)-fulvic acid complex [95], molybdeniun(VI)-1,10 phenanthroline-fulvic acid complex [96], indigo [97], and reduction of vana-dium(V) [98] at a mercury electrode are some of the examples for surface electrode... 

Cresol red Crystal Violet Malachite Green Methanil Yellow Thymol Blue Orange IV -2,4-Dinitrophenol -Erythrosin, Na2 salt -Dimethyl Yellow Cl 11020 Bromophenol Blue Congo Red Cl 22120 Methyl Orange Bromocresol Green Alizarin Red S Cl 42750 Methyl Red Cl 13020 -Bromocresol Purple Chlorophenol Red p-Nitrophenol Alizarin Bromothymol Blue Brillant Yellow Phenol Red Neutral Red Cl 50040 -m-NItrophenol -Cresol Red Metacresol Purple Phenolphthalein -Thymolphthalein -P-Naphthyl Violet Alizarin Yellow R 2,4,6-T rinitrotoluene... 

Rats are sacrificed on gestation day 20. Fetuses are removed by cesarean section after noting the number of resorptions, implantations, and normal fetuses. The size, weight, and any abnormality of each fetus are noted. Two-thirds of the fetuses are eviscerated and then preserved in absolute alcohol for staining with Alizarin Red S for skeletal assessment. The other one-third of the fetuses is fixed in Allen s modification of Bonin s fluid for slicing with a razor blade (Wilson s Technique) to evaluate visceral anomalies. 

For rodents, one-half of the fetuses are submitted to a fixed soft tissue examination and half are submitted to skeletal examination (see Note 5). The ossified skeleton of the remaining rodent fetuses is stained with alizarin red (see Chapter 16). Additional staining of the cartilage with alcian blue (see Chapter 17) is optional. Allocation of the fetuses within each litter to soft tissue or skeletal examination is performed alternately or randomly. 

Approximately one half of each litter is eviscerated and the eviscerated fetal carcasses are fixed and processed for skeletal examination. The skeletal examinations are performed following maceration of the soft tissues with aqueous potassium hydroxide, staining of the skeleton with Alizarin red, and then passage into glycerol. 

Alizarin red (0.2 g alizarin-sulphonic acid-natrium salt in 4,000 mL of 1% potassium hydroxide). 

Staining with alizarin red for 18-24 h Ossified bones are stained red to purple, cartilage is stained light pink. 

Key words Skeletal examination. Alizarin Red S staining, Teratology, Preclinical methods, Developmental toxicity. Embryo-fetal development, Embryo-toxicity... 

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