MOI calculation
The Multiplicity of Infection (MOI) is calculated according to the Bac-N-Blue Transfection and Expression Guide Invitrogen manual by performing a plaque assay on the 4th amplification of the baculovirus making dilutions of 1/104 to 1/108. Plates are incubated for about 7-10 days in order to obtain and count well spread blue colonies. The MOI is based on the formula:
MOI = ((Volume of virus)(dilution)(number of plaques))/(total volume x cells/ml)
Example: we have 105 colonies in the dilution 1x10^6, that is 1.05x10^8.
600ml x 1.8 x 10^6 = 10.8 x 10^8
Volume cells used
of virus
Virus used = MOI x 10.8 x 10 ^ 8 x 1/1.05 x 10 ^8
MOI= 60 x 1.05 x 10 ^8/10.8 x 10 ^8 = 5.8
MOI=5.8