Detection of grass pollen proteins such as Pas n 1, Sor h 1 and/or Cyn d 1 for the purpose of batch standardization of compositions comprising these grass pollen proteins, such as used for desensitization to these allergenic proteins. The methods may also be suitable for detecting or measuring levels of grass pollen proteins such as Pas n 1, Sor h 1 and/or Cyn d 1 in environmental samples such as air or water. Also provided is an antibody or antibody fragment engineered to bind Pas n 1 and one or a plurality of other grass pollen proteins such as Sor h 1 and/or Cyn d 1.
