Hi Jaya,

An MOI of 1 is equal number of cells and virus particles. So in your case you would use 2ul of virus for 10,000 cells. An MOI of 2 would be twice the number of virus particles compared to cells.

It is difficult to answer your second question since you do not mention the cell type you are infecting. Different cell types require different MOIs to achieve a particular transduction efficiency. You should check the literature to see what MOIs people use.

Good Luck!

Dear Jaya,

MOI is related to pfu by the following formula:

Multiplicity of infection (moi) = Plaque forming units (pfu) of virus used for infection / number of cells.

For example, if 2x106 cells is infected by 50 ml of virus with a titer of 108 pfu/ml. The moi will be 0.05*108/2*106 = 2.5

See more in the attached 

http://www.nature.com/mt/journal/v2/n5/pdf/mt2000190a.pdf%3Forigin%3Dpublication_detail

Thank you all for the reply

Hello dear Jaya,

Regarding MOI, you can calculate simply making equal ratio of virus particle to cells to be infected. In this typical question, the titre of your virus is 5000 particles/ul, where as you are trying to infect with 10, 000 cells. So according to your virus titre and MOI of 1, you will use 2ul of the virus solution.

Regarding the 50% confluency of cells on 12 well plate, I suggest that you should check microscopy.

Thank you. I will

MOI x total amount of cells

____________________________ = volume seed virus (mL)

Titre seed virus (CCID50/mL)

How could I calculate the amount of bacteria to be added from thr resuspended bacteria to achieve a certain MOI ? does it depend on the cells seeded ? how come since the cells seeded are now confulent and way more ? I seeded 4000 and want an MOI of 250

MOI =ratio of phage to bacterial cells.phage concentration can be measured by double soft agar method and bacterial concentration by diltution method ,simple.

MOI=1 means f you have 1000 phage particles and 1000 bacterial cells.

Phage con. you can estimate by double layer soft agar method and bacterial load can beestimated by mishra dilution method.

MOI=0.1 means if you have 100 phage particles and 1000 bcaterial cells.

The Multiplicity of infection (MOI):

1 cell = 1 virus: means MOI =1.

For your 10000 cells considering MOI =1,

you have 5000 viral particles in 1 uL,

10000 cells = 5000 x 2 uL (i.e. 10000 viral particle means MOI =1)

it is a ratio of virus titer (TCID50) divided by cell No

10^6 = 1000000 virus

CElls = 1000 000

Ratio = 1000000/1000000= 1

So MOI = 1

MOI(Multiplicity of infection) means the ratio of phage particles and bcaterial cells.

MOI=phage particles/ bcaterial cells

Hello,

How to know phage particles in a solution?

MOI=phage particles/ bacterial cells

I want to calculate the MOI of unknown phage.