Concentration of Viruses from Seawater
111
cellulose acetate or fiberglass filters for removal of virus. The virus-retaining filters were
washed with 1 gallon of physiologic saline to remove residual hypertonic fluids. Virus
elution was carried out as described previously and the eluate assayed. The results are
given in Table 2. Little or no virus was removed by the orlon clarifiers and less than 5
percent of the total virus passed the virus adsorbents in two of three trials. When large
numbers of virions were used, 12 percent of the total virus passed a cellulose acetate
filter. Of the virus retained by the filter, 97 percent was recovered in the eluate.
The results of several experiments established a basis for concentration of viruses from
seawater. Clarifying filters such as orlon could be used to remove marine silts or debris
without significant loss of virus. Clarified seawater could then be passed through cellulose
acetate or fiberglass filters with retention of virus by these filters. Elution of virus from
these filters can be accomplished with recovery of virus in eluates. Reconcentration of
virus as described (Wallis, Homma and Melnick, 1972b) leads to recovery of virtually all
of the initial virus in a 10 ml eluate.
The effectiveness of clarifying and virus adsorbing functions of textile filters in polluted
natural salt waters.
The Houston, Texas, ship channel was sampled over a 12 mile distance for the
presence of substances interfering with the virus-retaining capacity of cellulose acetate
and fiberglass filters. Volumes of water from 2.5 to 40 gallons were passed first through
orlon clarifying filters, then through cellulose acetate and fiberglass filters in parallel
arrangement. The virus collecting filters were challenged with known numbers to
determine whether alteration of the virus retentivity character of a filter had occurred.
The results of the series of tests are given in Table 3. Fiberglass filtrates showed little or
no penetration of virus had occurred when compared to the untreated control. Cellulose
acetate filtrates showed a direct relationship between volume of water sample and
penetration of filters by virus. Based upon virus penetration of test filters, MCC were
considered to be present in the water and to affect the virus adsorbing quality of cellulose
acetate, but not fiberglass, filters.
Estuary water at Galveston, Texas, was examined for its effect upon the virus
adsorbing quality of fiberglass and cellulose acetate filters. Water samples of 5 to 320
gallons were passed through orlon filters for clarification, then through the two virus
adsorbing filters in parallel. Each of the test filters received samples of 2.5 to 160 gallons.
The virus adsorbing quality of the test filters was determined by subjecting each filter to
virus challenge followed by examination of filtrates for filter penetrating virus. The
results of a series of experiments are given in Table 4. The two virus adsorbing filters both
showed penetration of virus, cellulose acetate being affected more than fiberglass. Virus
penetration was uniform for each adsorbent filter regardless of the volume of the water
sample filtered. There was no indication of alteration of the virus adsorbing quality of
either filter with increasing volumes of seawater up to 160 gallons. Failure to show a
significant pattern of adsorptive alteration in either series of tests was interpreted as
evidence of filter insensitivity to any MCC effects possessed by the estuary water.
The orlon clarification filters were tested for their ability to promote passage of virus
in the presence of heavy depositions of marine silt and debris. One gallon volumes of a
virus solution were passed through each filter and the filtrates tested for virus. The results
of a series of tests are given in Table 5. No significant pattern of impairment of virus
passage through the orlon filters was detected in the series of tests. The results suggested
that a single orlon filter could be used for clarification of seawater samples of 160 gallons
111
cellulose acetate or fiberglass filters for removal of virus. The virus-retaining filters were
washed with 1 gallon of physiologic saline to remove residual hypertonic fluids. Virus
elution was carried out as described previously and the eluate assayed. The results are
given in Table 2. Little or no virus was removed by the orlon clarifiers and less than 5
percent of the total virus passed the virus adsorbents in two of three trials. When large
numbers of virions were used, 12 percent of the total virus passed a cellulose acetate
filter. Of the virus retained by the filter, 97 percent was recovered in the eluate.
The results of several experiments established a basis for concentration of viruses from
seawater. Clarifying filters such as orlon could be used to remove marine silts or debris
without significant loss of virus. Clarified seawater could then be passed through cellulose
acetate or fiberglass filters with retention of virus by these filters. Elution of virus from
these filters can be accomplished with recovery of virus in eluates. Reconcentration of
virus as described (Wallis, Homma and Melnick, 1972b) leads to recovery of virtually all
of the initial virus in a 10 ml eluate.
The effectiveness of clarifying and virus adsorbing functions of textile filters in polluted
natural salt waters.
The Houston, Texas, ship channel was sampled over a 12 mile distance for the
presence of substances interfering with the virus-retaining capacity of cellulose acetate
and fiberglass filters. Volumes of water from 2.5 to 40 gallons were passed first through
orlon clarifying filters, then through cellulose acetate and fiberglass filters in parallel
arrangement. The virus collecting filters were challenged with known numbers to
determine whether alteration of the virus retentivity character of a filter had occurred.
The results of the series of tests are given in Table 3. Fiberglass filtrates showed little or
no penetration of virus had occurred when compared to the untreated control. Cellulose
acetate filtrates showed a direct relationship between volume of water sample and
penetration of filters by virus. Based upon virus penetration of test filters, MCC were
considered to be present in the water and to affect the virus adsorbing quality of cellulose
acetate, but not fiberglass, filters.
Estuary water at Galveston, Texas, was examined for its effect upon the virus
adsorbing quality of fiberglass and cellulose acetate filters. Water samples of 5 to 320
gallons were passed through orlon filters for clarification, then through the two virus
adsorbing filters in parallel. Each of the test filters received samples of 2.5 to 160 gallons.
The virus adsorbing quality of the test filters was determined by subjecting each filter to
virus challenge followed by examination of filtrates for filter penetrating virus. The
results of a series of experiments are given in Table 4. The two virus adsorbing filters both
showed penetration of virus, cellulose acetate being affected more than fiberglass. Virus
penetration was uniform for each adsorbent filter regardless of the volume of the water
sample filtered. There was no indication of alteration of the virus adsorbing quality of
either filter with increasing volumes of seawater up to 160 gallons. Failure to show a
significant pattern of adsorptive alteration in either series of tests was interpreted as
evidence of filter insensitivity to any MCC effects possessed by the estuary water.
The orlon clarification filters were tested for their ability to promote passage of virus
in the presence of heavy depositions of marine silt and debris. One gallon volumes of a
virus solution were passed through each filter and the filtrates tested for virus. The results
of a series of tests are given in Table 5. No significant pattern of impairment of virus
passage through the orlon filters was detected in the series of tests. The results suggested
that a single orlon filter could be used for clarification of seawater samples of 160 gallons