# Equation for calculating insert:vector ratio in ligation reaction - (Feb/26/2009 )

hi all

i am very much in need for the equations to carry out calculations before performing ligation, can any one plz help?

Hey

Equations? calculations? for ligation?

I am not sure if I understand what you mean to convey.

TC

sagar on Feb 26 2009, 11:57 PM said:

i am very much in need for the equations to carry out calculations before performing ligation, can any one plz help?

Do you need the ligation recipe or how to calculate the vector-insert ratio? Please be more specific.

insert mass in ng = 6 X (insert lenght in bp/vector lenght in bp) X vector mass in ng

You may change the 6 above depending on the actual ratio you want to get (sometimes a 3:1 works best than 6:1)

planktonica on Mar 4 2009, 01:16 PM said:

You may change the 6 above depending on the actual ratio you want to get (sometimes a 3:1 works best than 6:1)

One thing to mention, you have to get pure vector and insert before applying this equation. Sometimes RNA contamination will lead to incorrect calculation.

Try 3:1 and 1:1 insert to vector ratio, these two ratio usually rock in ligation reaction.

Hi Sagar,

Go to the 'Biomath Calculator' website using the following link.

http://www.promega.com/biomath/default.htm

Click on Ligations: Molar Ratio of Insert to Vector

Enter the parameters of your ligation and it will calculate the relative amounts for you.

Easy!