space
Determination of functional viral titer (TU/ml) using the ZMC p24 Antigen ELISA

There are approximately 2000 molecules of p24 per physical particle (PP) of lentivirus:
(2 x 103) x (24 x 103 Da of p24 per PP), 48 x 106/Avogadro = (48 x 106) / (6 x 1023) =
8 x 10-17 g of p24 per PP, approximately 1 PP per 1 x 10-16 g of p24, 1 x 104 PP per pg of p24

A reasonably well packaged, VSV-G pseudotyped lentiviral vector will have an infectivity index in the range of 1 TU per 1000 physical
particles (PP) to 1 TU per 100 PP (or less). Thus, the range is approximately 10 to 100 TU/pg of p24. It is through this conversion that TU/ml is obtained.

This conversion is derived from Didier Trono to determine the relationship between pg/ml p24 and viral titer or MOI
and can also be found on the Sigma Aldrich FAQ site.

© Copyright 2000-2007 by ZeptoMetrix Corp. (ZMC) 1-800-274-5487 site map