Viral inactivation Virus processing

1 viral inactivation

1.1 solvent/detergent (s/d) inactivation
1.2 pasteurization
1.3 acidic ph inactivation
1.4 ultraviolet (uv) inactivation

viral inactivation

viral inactivation renders viruses inactive, or unable infect. many viruses contain lipid or protein coats can inactivated chemical alteration. viral inactivation different viral removal because, in former process, surface chemistry of virus altered , in many cases (now non-infective) viral particles remain in final product. rather rendering virus inactive, viral inactivation processes denature virus completely. viral inactivation used in blood plasma industry.

in order achieve inactivation of viruses in sample, necessary perform special purification processes chemically alter virus in way. of more used processes follows:

solvent/detergent inactivation
pasteurization (heating)
acidic ph inactivation

in cases viral inactivation not viable removal alternative because denatured or otherwise inactivated viral particles can have deleterious effects on process stream or product itself.

solvent/detergent (s/d) inactivation

this process, developed new york blood center, used viral inactivation method date. predominantly used in blood plasma industry, on 50 organizations worldwide , american red cross [1]. process effective viruses enveloped in lipid coat, however. detergents used in method interrupt interactions between molecules in virus s lipid coating. enveloped viruses cannot exist without lipid coating destroyed when exposed these detergents. other viruses may not destroyed unable reproduce rendering them non-infective. solvent creates environment in aggregation reaction between lipid coat , detergent happen more rapidly. detergent typically used triton-x 100.

chemical structure of triton x-100 (n = 9-10).

this process has many of advantages of traditional removal techniques. process not denature proteins, because detergents affect lipids , lipid derivatives. there 100% viral death achieved process , equipment relatively simple , easy use. equipment designed purify post-virus inactivated material necessary guard against contamination of subsequent process streams.

s/d treatment utilizes readily available , relatively inexpensive reagents, these reagents must removed product prior distribution require process steps. because process removes/inactivates lipid coating of virus, viruses without sort of lipid envelope unaffected. there no inactivation effect buffers used in process.

pasteurization

inactivation of viruses means of pasteurization can effective if proteins trying protect more thermally resistant viral impurities in solution. of more prominent advantages of these types of processes require simple equipment , effective both enveloped , non-enveloped viruses. because pasteurization involves increasing temperature of solution value sufficiently denature virus, not matter whether virus has envelope or not because envelope alone cannot protect virus such high temperatures. however, there proteins have been found act thermal stabilizers viruses. of course, if target protein not heat-resistant, using technique denature target protein viral impurity. typical incubation lasts 10 hours , performed @ 60°c.

acidic ph inactivation

some viruses, when exposed low ph, denature spontaneously. similar pasteurization, technique viral inactivation useful if target protein more resistant low phs viral impurity. technique effective against enveloped viruses, , equipment typically used simple , easy operate. type of inactivation method not effective non-enveloped viruses however, , requires elevated temperatures. in order use method, target protein must resistant low phs , high temperatures unfortunately not case many biological proteins. incubation process typically occurs @ ph of 4 , lasts anywhere between 6 hours , 21 days.

ultraviolet (uv) inactivation

uv rays can damage dna of living organisms creating nucleic acid dimers. however, damages not important due low penetration of uvs through living tissues. uv rays can used, however, inactivate viruses since virus particules small , uv rays can reach genetic material, inducing dimerisation of nucleic acids. once dna dimerised, virus particules cannot replicate genetic material prevent them spreading.

uv light in combination riboflavin has been shown effective in reducing pathogens in blood transfusion products.riboflavin , uv light damages nucleic acids in viruses, bacteria, parasites, , donor white blood cells rendering them unable replicate , cause disease.