SEMEN
Semen is a complex gelatinous mixture of cells, amino acids, sugars, salts, ions, and other materials produced by postpubescent males and is ejaculated following sexual stimulation. The volume of ejaculate varies from 2 to 6 mL and typically contains between 100 and 150 million spermatozoa, or sperm cells, per milliliter. Sperm cells, are a specialized structure approximately 55 µm in length with a head containing DNA and a tail that wiggles, or flagellates, to produce movement. The presence of semen (or, by extension, intact sperm) is considered presumptive evidence of sexual contact.
FIGURE 1 This is an Ouchterlony Double Diffusion method gel. The central well contains an antibody and the surrounding wells contain the corresponding antigen in decreasing concentration (“Neat,” “(1:1),” “1:2,” “1:4,” “1:8,” “1:16,” and “1:32”). The line that runs from top center to bottom center stops at the titer value, 1:8.
FIGURE 2 In electrophoresis antibodies and antigens diffuse on an electrically charged gel-coated plate forming a juncture.
