PA Alternative (actually alternative to modified PA)

Virus titration using end-point dilution technique is a common practise introduced by Reed and Muench (1938). Instead of PFU/mL, units are EID50/mL - i.e. in terms of dilutions at which 50% of viral efficacy is observed. 

Sample calculations are found at:

• http://74.125.47.132/search?q=cache:bZn9di4M2pAJ:www.fao.org/DOCREP/005/AC802E/ac802e0f.htm+reed+muench+titration&hl=en&ct=clnk&cd=1&gl=us
  
• http://74.125.47.132/search?q=cache:DJiRMUq8gHYJ:www.fao.org/docrep/005/ac802e/ac802e0w.htm+reed+muench+titration&hl=en&ct=clnk&cd=2&gl=us
  

Efficient alternative was developed using GFP in 1997. Paper retrieved using ILLIAD:

"Biotechniques.: Simplification of titer determination for recombinant baculovirus by green fluorescent protein marker"

HJ CHA, T GOTOH, WE BENTLEY - BioTechniques, 1997