Disclosed is an immunoassay method for detecting an analyte such as an antigen or an antibody in an isolated sample suspected to contain the analyte by incubating the sample with a plurality of binding partners, one of which carries a detectable label, wherein a label-specific binding partner is added that does not carry a label but binds to the detectable label. The method is applicable for a large variety of analytes and has proven particularly useful for analyte antibodies of the IgG and IgM class present in samples due to infections by pathogens. Also disclosed is a reagent kit useful for the method comprising at least two analyte-specific binding partners one of which carries a detectable label and a label-specific binding partner that binds to said detectable label but itself does not carry a detectable label.

Disclosed is an immunoassay method for detecting an analyte such as an antigen or an antibody in an isolated sample suspected to contain the analyte by incubating the sample with a plurality of binding partners, one of which carries a detectable label, wherein a label-specific binding partner is added that does not carry a label but binds to the detectable label. The method is applicable for a large variety of analytes and has proven particularly useful for analyte antibodies of the IgG and IgM class present in samples due to infections by pathogens. Also disclosed is a reagent kit useful for the method comprising at least two analyte-specific binding partners one of which carries a detectable label and a label-specific binding partner that binds to said detectable label but itself does not carry a detectable label.

A method of purification of non-enveloped or pseudo-enveloped virus produced in vitro uses a composition with at least one detergent. A method of purification can use multiple detergents, and a method of determining the presence and/or level of a non-enveloped or pseudo-enveloped virus in a sample includes treating with at least one detergent.