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Biomedical subjects

J L Melnick

Publications and source records attributed to J L Melnick.

At least 307 records · Page 17Linked to original sources
PubMed1971

Concentration and purification of viruses by adsorption to and elution from insoluble polyelectrolytes.

Acid-resistant, nonenveloped viruses belonging to the enterovirus, reovirus, and adenovirus groups were readily concentrated on PE60, an insoluble cross-linked polyelectrolyte based on isobutylene maleic anhydride. Hydrolysis of PE60 by NaOH increased its capacity to adsorb viruses. Hydrogen ion levels played an important role in virus concentration; optimal pH levels for maximal virus adsorption were between pH 3.0 and 4.5. Undiluted virus was easily concentrated from large volumes on PE60, and the adsorbed virus was readily eluted at pH 8 to 9.

Adenoviridae↗
PubMed1971

Enhanced detection of Australia antigen in serum hepatitis patients by discontinuous counter-immunoelectrophoresis.

The use of discontinuous counter-immunoelectrophoresis enhanced the reaction between Au/SH antigen and its antibody in agarose. The ionic strength of the Veronal buffer used in the agarose was 0.015 mu, whereas 0.075 mu Veronal (both pH 8.6) was used for anode and cathode buffers. Electroendosmosis is increased under such conditions. Au/SH antigen and antibody reacted to give sharp lines within 30 to 45 min as compared with conventional counter-immunoelectrophoresis which required 1 to 3 hr or longer.

Hepatitis B↗
PubMed1971

Evaluation of enterovirus immune horse serum pools for identification of virus field strains.

Immune horse sera to 42 enterovirus immunotypes were pooled according to the Lim Benyesh-Melnick and the "intersecting serum" schemes. Each serum was diluted in the pools to contain 50 antibody units. After it was established that the pools correctly neutralized prototype virus strains, they were evaluated in tests against 273 enterovirus field strains representing most of the viral types included in the pools. With test virus doses of 10-100 TCD(50), most of the poliovirus and coxsackievirus field strains were correctly identified in both schemes, but a number of the echoviruses were neutralized by heterotypic pools, particularly in the Lim Benyesh-Melnick scheme. However, at higher test virus doses of 320-3200 TCD(50), little heterotypic neutralization occurred in either scheme, and 93-94% of the virus field strains were correctly identified in each scheme. With these larger virus doses, breakthrough tended to occur in homologous pools by the 7th day, but rarely by the 5th day. Since the Lim Benyesh-Melnick pool scheme employs 8 pools as compared with 13 for the intersecting serum scheme, and since the two schemes were equally satisfactory for identifying virus field strains at test virus doses of 320-3200 TCD(50), immune horse sera will be pooled by the former scheme, thus utilizing fewer pools, for distribution to qualified viral diagnostic laboratories.

Animals↗