scholarly journals A QUANTITATIVE STUDY OF THE FEULGEN REACTION WITH THE AID OF HISTOCHEMICAL MODEL SYSTEMS

1964 ◽  
Vol 12 (10) ◽  
pp. 752-757 ◽  
Author(s):  
M. J. HARDONK ◽  
P. VAN DUIJN

This paper reports some quantitative results with three histochemical model systems. The model systems are DNA-cellulose, deoxyadenylic acid-cellulose and deoxyguanylic acid-cellulose, and DNP-bovine albumin-polyacrylamide. By measuring the UV-absorption of the nucleotide-cellulose after various hydrolysis times, the rates of splitting-off of the purines by HCl were determined. Adenine is found to be split off twice as fast as guanine. The phosphorus/pararosaniline ratio is found to differ considerably from the theoretical value calculated on the assumption that every free aldehyde group reacts with pararosaniline. The differences in the values found for the phosphorus/pararosaniline ratio of the DNA-cellulose and the nucleotide-cellulose can be related to the differences in the absorption spectra of these models, which points to different degrees of substitution at the amino groups of pararosaniline. Addition of protein to DNP in a polyacrylamide film does not alter the phosphorus/pararosaniline ratio.

1964 ◽  
Vol 12 (10) ◽  
pp. 758-767 ◽  
Author(s):  
M. J. HARDONK ◽  
P. VAN DUIJN

The absorption spectra of Feulgen-stained deoxyribonucleic acid (DNA)-containing membranes have been studied under various conditions. The absorption curve of the Feulgen-stained DNA-cellulose differs from those of the other model systems and is comparable to that of a solution of apurinic acid stained by the Schiff reaction. The spectral shift caused by the reaction of formaldehyde and SO2 with the stained films was used as a criterion for the degree of substitution of the bound pararosaniline. The spectrum of DNA-cellulose, unlike the spectra of the other models, did not show any change under the action of these reagents. This indicates that the three amino groups of pararosaniline are all bound to the DNA in a stained DNA-cellulose film. When the mobility of the apurinic acid chain is restricted, the formation of the trisubstituted product is apparently hindered. Such a situation may be present in DNA-containing polyacrylamide films containing proteins and also in cell nuclei. From a study of the literature it is concluded that the shoulder in the pararosaniline spectrum is most probably caused by a configurational isomer of the dye as indicated by Lewis et al. (16) for crystal violet. To explain the abnormal spectrum of the stained DNA-cellulose, it is proposed that in this case pararosaniline is bound with the three amino groups to three neighbouring deoxyribose groups in the hydrolyzed DNA. Studies with Stuart models of the molecules involved showed that in this case one conformation isomer of pararosaniline can be constructed more easily than the other. This situation may explain the spectrum of the stained DNA-cellulose. The other spectral results could also be interpreted on basis of this hypothesis.


Author(s):  
James F. Hainfeld ◽  
Frederic R. Furuya

Glutaraldehyde is a useful tissue and molecular fixing reagents. The aldehyde moiety reacts mainly with primary amino groups to form a Schiff's base, which is reversible but reasonably stable at pH 7; a stable covalent bond may be formed by reduction with, e.g., sodium cyanoborohydride (Fig. 1). The bifunctional glutaraldehyde, (CHO-(CH2)3-CHO), successfully stabilizes protein molecules due to generally plentiful amines on their surface; bovine serum albumin has 60; 59 lysines + 1 α-amino. With some enzymes, catalytic activity after fixing is preserved; with respect to antigens, glutaraldehyde treatment can compromise their recognition by antibodies in some cases. Complicating the chemistry somewhat are the reported side reactions, where glutaraldehyde reacts with other amino acid side chains, cysteine, histidine, and tyrosine. It has also been reported that glutaraldehyde can polymerize in aqueous solution. Newer crosslinkers have been found that are more specific for the amino group, such as the N-hydroxysuccinimide esters, and are commonly preferred for forming conjugates. However, most of these linkers hydrolyze in solution, so that the activity is lost over several hours, whereas the aldehyde group is stable in solution, and may have an advantage of overall efficiency.


Author(s):  
Branislav Milovanović ◽  
Jurica Novak ◽  
Mihajlo Etinski ◽  
Wolfgang Domcke ◽  
Nadja Doslic

Despite many studies, the mechanisms of nonradiative relaxation of uracil in the gas phase and in aqueous solution are still not fully resolved. Here we combine theoretical UV absorption spectroscopy...


1969 ◽  
Vol 23 ◽  
pp. 2127-2135 ◽  
Author(s):  
Bengt Nelander ◽  
G. Hagen ◽  
Seija Vesala ◽  
Tarja Aalto ◽  
Per-Erik Werner ◽  
...  

Weed Science ◽  
1976 ◽  
Vol 24 (1) ◽  
pp. 107-114 ◽  
Author(s):  
V. E. Berkheiser ◽  
J. L. Ahlrichs

Ultraviolet (UV) absorption spectra were recorded of chloramben (3-amino-2,5-dichlorobenzoic acid) and selected relatives in solutions of different pH's. From these spectra, the Broensted acid-base properties of chloramben were deduced. Interpretations of solution spectra were applied to UV absorption spectra of chloramben adsorbed onto Ca-montmorillonite at low water content. Infrared (IR) transmittance spectra were recorded of chloramben and selected derivatives in KBr pellets and band assignments were made. Interpretations of these spectra were also applied to IR spectra of chloramben adsorbed onto Ca-montmorillonite at low water content. Both UV and IR measurements indicated that protonation of the amino group occurs and that the carboxyl group of chloramben is strongly hydrogen-bonded to the hydration water of the interlayer cations.


1983 ◽  
Vol 78 (9) ◽  
pp. 5351-5357 ◽  
Author(s):  
H. Hippler ◽  
J. Troe ◽  
H. J. Wendelken

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