SBIR-STTR Award

A dot-immunobinding assay (DIA) for detection of viral antibody as well as antigens has recently been described (1-7). The simplicity of the procedure, which is also rapid, specific, sensitive, and inexpensive, lends itself to commercialization as a kit for use in an unsophisticated laboratory or in the field. No equipment other than that provided in the kit is needed. In Phase I, an SIV kit will be prepared as this virus has already been shown to be adaptable to the DIA (see references 1,2,5). In Phase II, various parameters expanding the original studies will be examined in order to ascertain the full potential of this projected kit. Essentially, what antigens (principally viral) are satisfactory for detection of antibody and what conditions are necessary to detect antigen in specimens will be determined. The DIA now consist of dotting relatively crude known antigens on nitrocellulose (NC) sheets to which serum or blood is added by means of filter paper. After a period of absorption, the sheets are washed, treated with immunoglobulin-conjugate and then subjected to a substrate-dye which stains the antigen-antibody complex. The converse, i.e., unknown antigen, is placed on NC sheets and known antiserum is used to identify an antigen. The entire procedure takes approximately 3-5 hr.

The biomedical community continues to search for more rapid diagnostic procedures. Although the need is world-wide, procedures that require little in the way of sophisticated equipment and are relatively simple to perform are particularly desirable in developing countries. The dot-immunobinding assay (DIA) as described herein offers such a methodology. The specific aims of this Phase II project are: 1) to expand the preliminary studies funded by two SBIR program Phase I grants (R43 AI 29317 and R43 AI 28604. These studies clearly showed that the DIA in kit form may be used as a virus diagnostic test in the non-laboratory setting for detecting HIV or herpes B antibody; 2) to expand the testing of sera to include selected viral antigens; 3) to compare the crude viral lysates currently in use with more specific and sensitive HIV reagents such as gene products, synthetic polypeptides, and recombinant antigens; 4) to explore in greater detail the use of whole blood in the DIA rather than serum; and 5) examine kit modifications in order to provide appropriate testing of single or multiple serum or blood samples.