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The memberane Piece Technique for in Vitro Infectivity Titrations of Influenza Virus

Published online by Cambridge University Press:  15 May 2009

N. B. Finter
Affiliation:
Public Health Laboratory, Northampton
P. Armitage
Affiliation:
Statistical Research Unit of the Medical Research Council, London School of Hygiene and Tropical Medicine
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1. The membrane piece technique for in vitro titrations of the infectivity of influenza virus is described. Rectangles of shell, about 8 × 25 mm., with the chorio-allantoic membrane still attached (membrane pieces) are cut from thirteenth-day fertile eggs. One piece in a test-tube with glucose-buffered salt solution forms an individual assay unit. Five or more tubes are inoculated with each virus dilution. After incubation at 37° C. for 72 hr., with agitation for the first 24 hr. the fluid in each tube is tested for haemagglutinins. From the results at each dilution, an estimate of the 50% membrane piece (MP50) infectivity titre is obtained.

2. Six hundred assay units, with pieces cut from twenty eggs, can be set up by two workers in 1 hr. and used for titration of between three and twenty-four individual virus preparations, depending on the reliability desired for the 50% end-point estimates.

3. With the D.S.P. and PR 8 strains of influenza A virus, the MP50 titres parallel the EID50 titres from egg titrations, but are eight times and twenty times lower, respectively. The MP50: EID50 ratio is the same for various preparations of the same strain, including standard allantoic fluid and chorio-allantoic membrane virus, incomplete virus, and inactivated (heated) allantoic fluid virus. Preliminary experiments with Lee influenza B virus show that slightly different experimental conditions are required, and the MP50 titres are about fifty times less than the EID50 titres.

4. Consistent results have been obtained on titration of samples of the same virus preparation on a number of occasions over a period of several months.

5. A large number of membrane pieces can be used to test each virus dilution, and sampling variations in the MP50 estimates thus made quite small. Statistical data on the reliability of a 50 % titration result, and on the minimum significant differences between two end-points, are given for different values of n, the number of membrane pieces used to test each virus dilution, and of d, the log dilution step.

We are grateful to Mr J. Collins for invaluable technical assistance, and also to Miss I. Allen for help with the computations.

Type
Research Article
Copyright
Copyright © Cambridge University Press 1957

References

Asmitage, P. & Spicer, C. C. (1956). The detection of variation in host susceptibility in dilution counting experiments. J. Hyg., Camb., 54, 401.CrossRefGoogle Scholar
Beale, A. J. & Finter, N. B. (1956). The infectivity of chorio-allantoic membrane influenza virus and incomplete influenza virus by the six-hour soluble antigen production test. J. Hyg., Camb., 54, 68.CrossRefGoogle ScholarPubMed
Berkson, J. (1955). Estimate of the integrated normal curve by minimum normit chisquare with particular reference to bio-assay. J. Amer. statist. Ass. 50, 529.CrossRefGoogle Scholar
Fazekas de St Groth, S. (1955). Production of non-infective particles among influenza viruses: Do changes in virulence accompany the von Magnus phenomenon? J. Hyg., Camb., 53, 276.CrossRefGoogle ScholarPubMed
Finter, N. B. & Beale, A. J. (1956). The 6-hour soluble antigen production test for comparing the infectivity of influenza virus preparations. J. Hyg., Camb., 54, 58.CrossRefGoogle ScholarPubMed
Fulton, F. & Armitage, P. (1951). Surviving tissue suspensions for influenza virus titrations. J. Hyg., Camb., 49, 247.Google Scholar
Fulton, F. & Isaacs, A. (1953). Influenza virus multiplication in the chick chorio-allantoic membrane. J. gen. Microbiol. 9, 119.CrossRefGoogle Scholar
Gajdusek, D. C. (1953). Suspended cell tissue cultures for study of virus growth kinetics. Proc. Soc. exp. Biol., N.Y., 83, 621.CrossRefGoogle ScholarPubMed
Granoff, A. (1955). Plaque formation with influenza strains. Virology, 1, 252.CrossRefGoogle ScholarPubMed
Henle, W. (1950). Interference phenomena between animal viruses; a review. J. Immunol. 64, 203.CrossRefGoogle ScholarPubMed
Henle, W. & Rosenberg, E. B. (1949). One-step growth curves of various strains of influenza A and B viruses and their inhibition by inactivated virus of the homologous type. J. exp. Med. 89, 279.CrossRefGoogle Scholar
Horváth, S. (1954). A new sensitive method of the rolling drum type for influenza virus titration. Acta microbiol. 1, 481.Google ScholarPubMed
Hoyle, L. (1948). The growth cycle of influenza virus A. A study of the relations between virus, soluble antigen and host cell in fertile eggs inoculated with influenza virus. Brit. J. exp. Path. 29, 390.Google ScholarPubMed
Knight, C. A. (1944). Titration of influenza virus in chick embryos. J. exp. Med. 79, 487.CrossRefGoogle ScholarPubMed
Ledinko, N. (1955). Production of plaques with influenza viruses. Nature, 175, 999.CrossRefGoogle ScholarPubMed
Luria, S. E. (1953). General Virology, p. 50. London: Chapman & Hall.Google Scholar
Moran, P. A. P. (1954). The dilution assay of viruses. J. Hyg., Camb., 52, 189.CrossRefGoogle ScholarPubMed
Peto, S. (1953). A dose-response equation for the invasion of micro-organisms. Biometrics, 9, 320.CrossRefGoogle Scholar
Tamm, I., Folkers, K. & Horsfall, F. L. (1953). Inhibition of influenza virus multiplication by alkyl derivatives of benzimidazole. J. exp. Med. 98, 229.CrossRefGoogle ScholarPubMed
Tamm, I., Folkers, K., Shunk, C. H. & Horsfall, F. L. (1954). Inhibition of influenza virus multiplication by N-glycosides of benzimidazoles. J. exp. Med. 99, 227.CrossRefGoogle ScholarPubMed
Tamm, I. & Tyrrell, D. A. J. (1954). Influenza virus multiplication in the chorioallantoic membrane in vitro: kinetic aspects of inhibition by 5,6-dichloro-l-β-D-ribofuranosyl-benzimidazole. J. exp. Med. 100, 541.CrossRefGoogle Scholar
Thompson, W. R. (1947). Use of moving averages and interpolation to estimate median-effective dose. Bact. Rev. 11, 115.CrossRefGoogle ScholarPubMed
Tyrrell, D. A. J. & Tamm, I. (1955). Prevention of virus interference by 2,5-dimethyl-benzimidazole. J. Immunol. 75, 43.CrossRefGoogle Scholar
Von Magnus, P. (1951a). Propagation of the PR8 strain of influenza A virus in chick embryos. I. The influence of various experimental conditions on virus multiplication. Acta path. microbiol. scand. 28, 250.CrossRefGoogle ScholarPubMed
Von Magnus, P. (1951b). Propagation of the PR 8 strain of influenza A virus in chick embryos. II. The formation of incomplete virus following inoculation of large doses of seed virus. Acta path. microbiol. scand. 28, 278.CrossRefGoogle Scholar
Weil, C. S. (1952). Tables for convenient calculation of median-effective dose (LD50 or ED50) and instructions in their use. Biometrics, 8, 249.CrossRefGoogle Scholar
Wunder, C. C., Brandon, F. B. & Brinton, C. C. (1954). Assay of influenza virus activity with chick embryonic membranes. Proc. Soc. exp. Biol., N.Y., 86, 561.CrossRefGoogle Scholar