Patent ID: 7625708

Claim:
A method of detecting exposure of a subject to a chemical, comprising: collecting a hair sample having an intact hair follicle bulb from the subject; digesting an outer root sheath of the hair follicle bulb from the hair sample; blocking the hair follicle bulb; dual labeling the hair follicle bulb by: incubating the hair follicle bulb with a primary antibody to bind a first protein responsive to the chemical; demonstrating the bound first protein in the hair follicle bulb by incubating the hair follicle bulb with a first dye-labeled secondary antibody; incubating the hair follicle bulb with a positive control antibody to bind a second protein indicative of a growth stage of the hair follicle bulb; and demonstrating the bound second protein in the hair follicle bulb by contacting the hair follicle bulb with a second dye-labeled secondary antibody; detecting a change in level of the second protein from the hair follicle bulb as an indication of the growth stage of the hair follicle bulb; and detecting a change in level of the first protein from the hair follicle bulb as an indication of exposure to the chemical if the detected level of the second proteins is indicative of the hair follicle bulb being in a desired growth stage at a time of collecting the hair sample, and wherein the desired growth stage of the hair follicle bulb is an anagen growth stage.