Seminal stains

In the event that the LDH system does not solve the problem of seminal stain identification, research has been initiated to produce specific antisera to certain antigens only found in seminal fluid. Preliminary work indicates that at least five constituents of seminal fluid can be electrophoretically separated and antigenically introduced into rabbits (28, 29). 

I shall describe the useful properties of photoluminescence and the current application of these properties in forensic science. New applications of photoluminescence developed or being investigated in our laboratory are also described. We have used photoluminescence techniques to (a) locate and identify seminal stains, (b) detect lead and antimony gunshot residue at the nanogram level, and (c) discriminate between different glass and human (head) hair samples. All of these techniques can be carried out rapidly in the crime laboratory. 

Seminal Stains As previously reported, we have used luminescence decay properties to detect the presence of semen on strong fluorescent backgrounds (12). We have recently extended the use of this technique as an aid in the identification of semen (13). 

In the crime laboratory, absolute proof that a stain is of seminal origin is only afforded by the microscopic observation of intact spermatozoa. However, one laboratory reported that spermatozoa were observed in only approximately 50 of the cases where a stain was suspected to be of seminal origin. In cases where no spermatozoa are found, alternate methods have been developed for seminal stain "identification."... 

Two methods commonly used to test for seminal stains are the acid phosphatase test and the Florence test. Both tests were developed on the basis of the reaction of an introduced compound with substances that are present in seminal fluid. Positive results for these tests are either the formation of a characteristic color or the formation of specific crystals. Since the substances tested are also present in other body fluids and in vegetable juices, the specificity of these tests has been questioned (lh). 

The final paper in this volume (Jones) is concerned with the application of a less familiar technique, photoluminescence, to a wide range of investigations, including sensitive firearm residue detection, the discrimination between different glass, polymer, and hair samples, and the identification of seminal stains. The promise here is of relatively inexpensive equipment with wide applicability in the criminalistics laboratory. 

EP. Smith and D.A. Pomposini. Detection of phenobarbital in bloodstains, semen, seminal stains, saliva, saliva stains, perspiration stains, and hair. /. Forensic Sci. 26 582-586, 1981. 

Lasers (qv) and other high intensity or alternative light sources are usefiil in crime laboratories to visualize latent fingerprints, seminal fluid stains, obhterated writings, and erasures, and to aid in specialized photographic work. Infrared and ultraviolet light sources are also used to view items of evidence. 

In 1991 Shi et al. published their seminal observation that high-temperature incubation of formalin-fixed, paraffin-embedded (FFPE) tissue sections in buffers for short periods led to improved immunohistochemical staining.1 However, more than 15 years later, heat-induced antigen retrieval (AR) remains largely an empirical procedure, requiring the optimization of several critical parameters by trial and error.2,3 Further improvements in AR will require an in-depth understanding of the chemistry of formaldehyde fixation and the molecular mechanism(s) underlying the AR method. 

The second goal is the selective staining of cells as well as luminescent imaging of analytes within cells. Indeed, spatial and temporal variations of analytes in five cells are vital information for the biochemist. In the course of an extensive and seminal investigation of... 

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