A kit and method for collecting body fluid for medical diagnosis. In some embodiments, the method includes collecting a sufficient amount of body fluid and cells comprising nucleic acid, and applying a nucleic acid assay to detect pathogenic genomic material such as human papillomavirus mRNA and/or human papillomavirus DNA. In some embodiments, by testing fluid and cells, a sensitivity of the test is improved. In some embodiments, the method includes inserting an absorbing member into a body orifice, such as the vagina, for a time period such as 1-2 hours； retrieving the absorbing member and placing it in a sample container； extracting fluid from the absorbing member using a fluid extraction device, and testing the fluid. In some embodiments, the kit is a home use kit and the sample is self collected by a user.
