ICT immunoassay for Legionella pneumophila serogroup 1 antigen employing affinity purified antibodies thereto

A device for determining the presence of Legionella pneumophila serogroup 1 in a liquid sample, the device comprising:

• a porous test strip comprising a sample receiving zone;
• multiple binding agents, each binding agent comprising:
• antigen specific affinity-purified polyclonal antibodies conjugated to a detectable particle, wherein the antigen specific affinity-purified polyclonal antibodies specifically bind a Legionella pneumophila serogroup 1 O-polysaccharide antigen and
• wherein the binding agents are essentially free of antibodies that bind proteins of Legionella pneumophila serogroup 1 O-polysaccharide;
• multiple capture agents;
• and
• a capture zone;
• wherein the porous test strip defines a liquid flow path extending downstream from the sample receiving zone and along which liquid received by the sample receiving zone can pass at least to the capture zone, the binding agents are disposed in a dried state along the flow path of the test strip downstream from the sample receiving zone and upstream from the capture zone, the binding agents are mobilizable by liquid passing along the flow path, and the capture agents are disposed in the capture zone and are each capable, in the presence of Legionella pneumophila serogroup 1 in a liquid sample received by the sample receiving zone, of binding a complex comprising one of the binding agents bound to the antigen.