This method was also effective for concentrating virus form large volume water samples . moreover / the concertration multiple of cyanophage pp could rise to nearly one - hundred times when two - step backflushing ultrafiltration technique was adopted 此法也适用于大量水样的处理，而且当采用两步反冲超滤技术时，噬藻体的浓缩倍数可以提升到近100倍。
