How to Calculate Oligo MW?

[Lawrence Washington]

In article <1994Nov3.140526.1 at mcvax4.d48.lilly.com>,
books at mcvax4.d48.lilly.com wrote:
> 
> We are looking for a formula to calculate the exact MW for oligonucleotides.
> The oligo will have a 5'-hydroxy group. We can estimate oligonucleotide MW
> if we use 330 as the average MW for each base but we need a exact number. 
> Thanks DPSMITH smith_dennis_p at lilly.com

from the Pharmacia catalog's Technical Notes:

MW=[(dA x 312.2)+(dC x 288.2)+(dG x 328.2)+(dT x 303.2)] - 61.0