We thank L. Dabo for assistance with mouse genotyping and A. McArthur for editing the manuscript.

No abstract

Background: The RB1 gene was the first tumor suppressor gene cloned from humans by studying genetic lesions in families with retinoblastoma. Children who inherit one defective copy of the RB1 gene have an increased susceptibility to retinoblastoma. Several years after the identification of the human RB1 gene, a targeted deletion of Rb was generated in mice. Mice with one defective copy of the Rb gene do not develop retinoblastoma. In this manuscript, we explore the different roles of the Rb family in human and mouse retinal development in order to better understand the speciesspecific difference in retinoblastoma susceptibility.

Tests for the identification of semen commonly involve the microscopic visualization of spermatozoa or assays for the presence of seminal markers such as acid phosphatase (AP) or prostate-specific antigen (PSA). Here, we describe the rapid stain identification kit for the identification of semen (RSID™-Semen), a lateral flow immunochromatographic strip test that uses two antihuman semenogelin monoclonal antibodies to detect the presence of semenogelin. The RSID™-Semen strip is specific for human semen, detecting <2.5 nL of semen, and does not cross-react with other human or nonhuman tissues tested. RSID™-Semen is more sensitive with certain forensic evidence samples containing mixtures of vaginal secretions and semen than either of the commercially available PSA-based forensic semen detection tests or tests that measure AP activity that were tested in parallel. The RSID™-Semen kit also allows sampling a fraction of a questioned stain while retaining the majority of the sample for further processing through short tandem repeat analysis.

Current methods for forensic identification of saliva generally assay for the enzymatic activity of alpha-amylase, an enzyme long associated with human saliva. Here, we describe the Rapid Stain IDentification (RSID-Saliva), a lateral flow immunochromatographic strip test that uses two antisalivary amylase monoclonal antibodies to detect the presence of salivary amylase, rather than the activity of the enzyme. We demonstrate that RSID-Saliva is accurate, reproducible, and highly sensitive for human saliva; RSID-Saliva detects less than 1 microL of saliva. The sensitivity of RSID-Saliva allows investigators to sample a fraction of a questioned stain while retaining the majority for DNA-STR analysis. We demonstrate that RSID-Saliva identifies saliva from a variety of materials (e.g., cans, bottles, envelopes, and cigarette-butts) and it does not cross-react with blood, semen, urine, or vaginal fluid. RSID-Saliva is a useful forensic test for determining which evidentiary items contain saliva and thus may yield a DNA profile.