Alternative Concentration Method	Advantages	Disadvantages
Ultracentrifugation	Little co-concentration of large molecules or particulates, relatively simple in concept and execution	Cannot achieve high-fold concentration, increased risk of contamination, cumbersome, cannot process large volumes
Ultrafiltration	Relatively easy to process medium-to-large volumes	Cannot achieve high-fold concentration, increased risk of contamination, large amount of vector trapped in filters, co-concentrates negatively charged species such as phenol red
Chromatography	Inexpensive, no specialized equipment, little co- concentration of large molecules or particulates	Processing medium-to- large volumes extremely cumbersome