Shendra Passic, MS 1 ; Brian Wigdahl, PhD 1 ; Gustavo Doncel, PhD 2 ; and Fred Krebs, PhD 1 1 Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; and 2 CONRAD, Arlington, Virginia Testing conducted for CONRAD at the Drexel University College of Medicine identifies compounds that may be used to reduce or eliminate the risk of human immunodeficiency virus type 1 (HIV-1) sexual transmission. Ideal compounds would have little or no cytotoxicity and fast-acting activity against multiple strains and subtypes of cell-free and cell- associated HIV-1. This in vitro testing algorithm includes assays to screen approximately 15 compounds per month. Testing begins with a cytotoxicity screen to assess the im- pact of each compound on cell viability and to guide the selection of concentrations to be used in antiviral testing. Activity against infectious HIV-1 is measured using viral binding/entry inhibition assays, in which each compound is evaluated for the ability to inhibit target cell infection by HIV-1 strains IIIB (X4 phenotype) or BaL (R5 phenotype). Finally, compounds are assessed for their ability to interfere with cell-to-cell HIV-1 transmission. For the evaluation of combinations that include 2 agents, an additional assay is employed to determine additive, synergistic, or antagonistic activity against HIV-1. The goal of this work is to identify compounds that have in vitro characteristics indicative of their potential as anti–HIV-1 microbicides. Using the CON- RAD testing algorithm, we evaluated 875 compounds be- tween May 2001 and January 2010. Several potential micro- bicide candidates were shown to have high selectivity indices (little or no cytotoxicity and consistently high ac- tivity in all 3 viral assays). These efforts will greatly facilitate the discovery of new compounds that can be used globally as microbicides. A Microbicidal Nipple Shield: An Innovative Method for Prevention of Mother-to-Child Transmission Of HIV Through Breastfeeding Sandra Urdaneta Hartmann, MD, PhD 1,2 ; Fred Krebs, PhD 1 ; Brian Wigdahl, PhD 1 ; David Sokal, MD 3 ; Mary Lynn Baniecki, PhD 3 ; Derek Owen, PhD 3 ; Stephen Gerrard, ME 4 ; and Elizabeth Kneen, MS 5 1 Department of Microbiology and Immunology, Drexel University College of Medicine, Philadelphia, Pennsylvania; 2 Institute for Women’s Health and Leadership, Drexel University College of Medicine, Philadelphia, Pennsylvania; 3 Family Health International, Durham, North Carolina; 4 Cambridge University, Cambridge, United Kingdom; and 5 Massachusets Institute of Technology, Cambridge, Massachusetts Globally, 17 million women of childbearing age are in- fected with HIV, half of them in Africa. Up to one third of their babies can become infected with HIV without any intervention. With prevention of perinatal transmission, 10% of infants become infected during breastfeeding. In low-resource settings, formula feeding is not feasible, as it causes more deaths than HIV. New WHO recommendations are to use anti-retroviral drugs to make breastfeeding safer, but resistance, cost, and side effects are issues. We previously reported that an ingredient in toothpaste, sodium dodecyl sulfate (SDS) kills HIV in breast milk in vitro, at concentra- tions as low as 0.01%–1%. Silicone nipple shields—sold over the counter for years—are discreet devices applied directly to the breast and can be used for solving problems during breastfeeding (eg, sore or inverted nipples). We are modify- ing a standard nipple shield to hold a nonwoven disk con- taining a microbicide that will inactivate HIV in breast milk. We are testing in vitro the effectiveness of SDS-containing filter disks in preventing HIV infection. Other safe-to-eat microbicides, previously reported on, will also be tested. Success of this work will allow HIV-positive women in low- resource settings to breastfeed their babies with a reduced risk of HIV transmission, presumably at a low cost. Maternal Plasma, as a Source for Fetal DNA, is Better than Fetal Cells for Noninvasive Prenatal Diagnosis of Single Gene Disorders Laura Hart, MD; Janet Ober, MS, CGC; Bhattacharya Anand, MHS; Yali Xiong, PhD; Owen Montgomery, MD; Laird Jackson, MD; and Ossie Geifman-Holtzman, MD Department of Obstetrics and Gynecology, Drexel University College of Medicine, Philadelphia, Pennsylvania Background: Noninvasive prenatal diagnosis (NIPD) using fetal material in maternal blood would provide a safe and accurate alternative to prenatal diagnosis by amniocentesis or chorionic villous sampling (CVS). Objective: Our aim was to determine the source of fetal material that was re- ported to achieve a higher accuracy of NIPD of single gene disorders. Methods: A PubMed search was performed for articles describing prenatal diagnosis of single gene disor- ders from maternal blood published to date and the data were reviewed. We tabulated the disorders and the source of the sample that was obtained from maternal blood, DNA from maternal plasma or from fetal cells isolated from ma- ternal blood. The accuracy of the diagnosis was calculated and the combined sensitivity, specificity, false positive rate, and false negative rate were calculated for all studies. Re- sults: We identified 43 articles describing 15 single gene disorders. The source of fetal material was maternal plasma and fetal cells in 28 and 15 of the studies, respectively. The NIPD from maternal blood of the following conditions was described: achondroplasia, sickle cell disease, hemoglobi- nopathies (thalassemia, hemoglobin Lepore, hemoglobin E, hemoglobin Bart‘s), myotonic dystrophy, congenital adre- nal hyperplasia, cystic fibrosis, Huntington disease, spinal muscular atrophy, and metabolic diseases. Accurate diagno- sis of single gene disorder was achieved in 187 of 218 sam- ples (86%) using fetal cells and 258 of 265 samples (97%) using fetal DNA. Conclusions: NIPD of single gene disor- ders using fetal DNA obtained from maternal plasma achieved a higher accuracy compared with fetal DNA ob- tained from fetal cells isolated from maternal peripheral blood. This higher accuracy demonstrates the potential of NIPD using fetal DNA to be clinically applicable and to possibly replace the traditional methods of prenatal diagno- sis through CVS and amniocentesis. A large multicenter study is required to demonstrate the clinical applicability of NIPD in the management of the pregnancy at risk. Modeling L-Selectin Mediated Attachment Strength during Embryo Implantation Monika Jost, PhD 1 ; Ken Barbee, PhD 2 ; Dianne Rothstein, PhD 3 ; Noreen Robertson, PhD 4 ; Poster Abstracts S95