A question about TPM normalization

[NikTuzov]

Hello:

Please tell me if I got it right. In the attached paper, the average read length, rl, is not necessary to know for computing TPM. It is sample-specific, but not gene-specific, and that is why it cancels out in the TPM formula and also in the formula that describes the relationship between TPM and RPKM.

Thanks,
Nik

[gpwagner]

readlength in TPM calculation

Dear Nick,

Yes the read length is canceling from the equation. The reason I left it in the equation is for conceptual clarity, to indicate what TPM is measuring. But yes, for calculating tpm you can forget rl.

Sincerely,
Gunter
(Gunter Wagner, Yale U)

[NikTuzov]

Thanks a lot.

Nik