Abstract: Compositions and methods for detecting the presence and/or amount of one or more analytes, including analytes such as drugs of abuse, are provided. The compositions include two or more analytes associated with a solid phase, e.g., a particle or a multiwell plate. The compositions and methods also allow the simultaneous, tandem, or serial determination of the presence and/or amount of two or more analytes of interest in a sample.

Abstract: Methods that permit the rapid release of one or more analytes from head or body hair or other keratinized structures of an individual (who may previously have ingested one or more of the analytes) are provided. The methods can include contacting the keratinized structure with a reducing agent but not with a proteolytic agent. The methods can further include identification and quantification of the one or more analytes by known analytical techniques such as immunoassays. The described methods do not damage the analyte and do not cause harmful effects on a subsequently-used analyte detection probe (e.g., an antibody).

Abstract: Methods that permit the rapid release of one or more analytes from head or body hair or other keratinized structures of an individual (who may previously have ingested one or more of the analytes) are provided. The methods can include contacting the keratinized structure with a reducing agent but not with a proteolytic agent. The methods can further include identification and quantification of the one or more analytes by known analytical techniques such as immunoassays. The described methods do not damage the analyte and do not cause harmful effects on a subsequently-used analyte detection probe (e.g., an antibody).

Abstract: Methods that permit the rapid release of one or more analytes from head or body hair or other keratinized structures of an individual (who may previously have ingested one or more of the analytes) are provided. The methods can include contacting the keratinized structure with a reducing agent but not with a proteolytic agent. The methods can further include identification and quantification of the one or more analytes by known analytical techniques such as immunoassays. The described methods do not damage the analyte and do not cause harmful effects on a subsequently-used analyte detection probe (e.g., an antibody).

Abstract: Methods that permit the rapid release of one or more analytes from head or body hair or other keratinized structures of an individual (who may previously have ingested one or more of the analytes) are provided. The methods can include contacting the keratinized structure with a reducing agent but not with a proteolytic agent. The methods can further include identification and quantification of the one or more analytes by known analytical techniques such as immunoassays. The described methods do not damage the analyte and do not cause harmful effects on a subsequently-used analyte detection probe (e.g., an antibody).

Abstract: Compositions and methods for detecting the presence and/or amount of one or more analytes, including analytes such as drugs of abuse, are provided. The compositions include two or more analytes associated with a solid phase, e.g., a particle or a multiwell plate. The compositions and methods also allow the simultaneous, tandem, or serial determination of the presence and/or amount of two or more analytes of interest in a sample.

Abstract: Methods that permit the rapid release of one or more analytes from head or body hair or other keratinized structures of an individual (who may previously have ingested one or more of the analytes) are provided. The methods can include contacting the keratinized structure with a reducing agent but not with a proteolytic agent. The methods can further include identification and quantification of the one or more analytes by known analytical techniques such as immunoassays. The described methods do not damage the analyte and do not cause harmful effects on a subsequently-used analyte detection probe (e.g., an antibody).