Preparation of mammalian deoxyribonucleic acid by SDS-phenol treatment

High concentration of RNA polymerase I is responsible for the high rate of nucleolar transcription

When isolated rat liver nuclei and nucleoli are compared for RNA synthesis in vitro, the rate of nucleolar RNA synthesis is found to be more than 10 times higher. In order to understand this high rate of nucleolar transcription, DNA from both nuclear and nucleolar fractions was isolated and compared for the ability to direct RNA synthesis with homologous RNA polymerases. No difference between these two templates is evident. On the other hand, when the total nuclear and nucleolar RNA polymerases are isolated and compared on a per-unit-weight-of-DNA basis, it becomes clear that the nucleolus has a 10-fold higher RNA polymerase concentration than the nucleus. This result suggests that RNA polymerase I concentration rather than the nucleolar DNA template efficiency is responsible for the observed high rate of nucleolar transcription under the normal steady-state condition.

Rapid separation of DNA constituents, bases, nucleosides and nucleotides, under the same chromatographic conditions using high-performance liquid chromatography with a reversed-phase column

Four components of three sets of DNA constituents, bases, deoxyribonucleosides and deoxyribonucleoside 5'-monophosphate, were sufficiently resolved under one set of chromatographic conditions using high-performance liquid chromatography with a reversed-phase column (Zorbax ODS) and the solvent 0.4 M NH4H2PO4 (pH 3.5). The effect of pH and salt concentration in the solvent on the retention of these compounds in the column was thoroughly investigated. Proportionality of peak height to the content, and reproducibility and recovery of the four bases were satisfactory under appropriate conditions and as little as 1 microgram of DNA could be analysed for its base composition by this method.

Reduction of the non-specific binding of DNA to gamma-globulin in Farr radioimmunoassay by addition of dextran sulfate and calcium chloride

The effect of non-specific binding caused by the interaction between gamma-globulin and denatured DNA was markedly reduced by addition of dextran sulfate or CaCl2 at alkaline pH. This method was shown to be applicable in the detection of anti-DNA antibodies in sera from cases of human systemic lupus erythematosus.

An adjuvant effect of poly A - poly U on production of antibodies to DNA in rabbits

The effect of polyadenylate-polyuridylate copolymer (poly A-poly U) on the formation of anti-DNA antibodies in rabbits was investigated. 1) Poly A-poly U proved to be an effective adjuvant for production of antibodies to DNA. These were elicited in rabbits at high titer and were formed at an early stage of immunizations. 2) The antiserum obtained reached potently with denatured DNA, but with neither methylated bovine serum albumin (MBSA) used as carrier protein nor poly A-poly U used as adjuvant. This was demonstrable both by C-fixation and double diffusion tests. 3) The antibodies occurred exclusively in the IgG fraction separated by Sephadex G-200 column chromatography.

A method for producing anti-DNA antibodies in ascitic fluid of mice

Immunological methods for the production of antibodies to DNA in ascitic fluid of DDY, A/He, and C57B1/6 mice were investigated. Relatively large volumes of ascitic fluid containing antibodies for DNA in high concentration were obtainable after seven injections of denatured ssDNA-MBSA complexes emulsified with CFA into peritoneal cavities of DDY mice. The quantity of anti-ascitic fluid from 4 to 5 DDY mice was equivalent to that of antiserum from one rabbit. DDY mice accumulation of ascites is much greater than in other strains, and the ascitic fluid contains antibodies of higher titer regardless of sex. The antibody titers in ascitic fluid are not affected by alteration of the ascites volume, and are proportional to those of the corresponding sera. Antibodies to DNA in ascitic fluid of these mice occurred exclusively in IgG as in DNA antisera.