Azoospermia
Definition
The absence of spermatozoa from ejaculated semen, resulting from obstructive causes (vasectomy, ductal blockage) or non-obstructive causes (testicular failure). Azoospermic semen contains full levels of PSA, so PSA immunoassay correctly identifies these samples as semen even when sperm microscopy is negative.
- Definition
- Absence of sperm in semen, congenital or acquired
- Common causes
- Vasectomy, spermatogenic failure
- Forensic impact
- Differential extraction cannot isolate sperm; recovery depends on epithelial cells
- Global prevalence
- Approximately 1% of men
Common questions
What does azoospermia mean in a forensic context?+
Azoospermia is the absence of sperm in semen, either from birth or acquired (like after a vasectomy). In forensic investigation, this matters because standard sperm-based DNA extraction won't work. Instead, examiners must rely on epithelial cells from the perpetrator to build a DNA profile.
Can you still find semen from an azoospermic person?+
Yes. Even without sperm, semen contains other cells and fluids. A sperm-negative result under the microscope doesn't rule out semen from someone with azoospermia. Forensic examiners use alternative recovery methods focusing on epithelial cells rather than spermatozoa.
How common is azoospermia?+
Azoospermia affects roughly 1% of men globally. It can result from obstructive causes like vasectomy or non-obstructive causes like spermatogenic failure (when the body fails to produce sperm).
Related terms
- Differential Extraction
- A two-step DNA extraction procedure used when a stain contains both sperm cells and non-sperm epithelial cells. The first step lyses epithelial...
- ABAcard P30
- A lateral-flow immunochromatographic strip manufactured by Abacus Diagnostics and validated by the Scientific Working Group for DNA Analysis Methods (SWGDAM) for forensic...
- Acrosome
- A cap-like organelle covering the anterior half of the sperm head. It contains hydrolytic enzymes used in oocyte penetration. Forensically it appears...
- Christmas Tree Staining
- A two-step differential stain using Nuclear Fast Red (Kernechtrot) to stain the sperm head red/pink and Picroindigocarmine to stain the midpiece and...
- Double-Swab Technique
- A collection method for dried biological stains in which a moistened swab rehydrates and lifts the stain from the surface, followed immediately...
- Epithelial Cell Fraction
- The non-sperm cellular material in a sexual assault sample. Contains skin and mucosal cells from both victim and any perpetrator who made...
- Ghost Head (Decapitated Spermatozoon)
- An isolated sperm head separated from its tail, commonly found in aged or dried stains. The head retains its oval morphology and...
- Lateral-Flow Immunochromatographic Assay
- A rapid, single-use immunoassay format in which sample extract migrates along a nitrocellulose membrane past a detection zone loaded with antigen-specific antibody...
- Prostate-Specific Antigen (PSA)
- A serine protease glycoprotein (also called p30) secreted in high concentrations by the prostate gland into seminal plasma. The primary immunological marker...
- PSA / P30
- Prostate-specific antigen, a kallikrein-family serine protease secreted by prostatic epithelium. Present in seminal plasma at 0.5 to 2 mg/mL. The standard confirmatory...
- RSID-Saliva
- Rapid Stain Identification of Saliva. An immunochromatographic lateral-flow assay using monoclonal antibodies specific to human salivary amylase. More specific than Phadebas, with...
- Salivary Alpha-Amylase
- An enzyme (EC 3.2.1.1) secreted by the parotid, submandibular, and sublingual glands. Digests starch and is present in saliva at concentrations of...
Explained in these topics
- Immunological Identification of Semen and SalivaThe absence of spermatozoa from ejaculated semen, resulting from obstructive causes (vasectomy, ductal blockage) or non-obstructive causes (testicular failure)...
- Semen, Saliva and Other Body Fluids as EvidenceThe absence of spermatozoa in seminal fluid, occurring in approximately 1% of men and in all vasectomised males. In these cases microscopic sperm search is neg...
- Spermatozoa Identification by MicroscopyThe absence of spermatozoa in ejaculate, whether due to obstructive causes (post-vasectomy) or non-obstructive causes (spermatogenic failure). Affects roughly...
- Swabbing Technique and DNA YieldAbsence of sperm in semen, either congenital or acquired (e.g., post-vasectomy). Relevant to forensic nursing because differential extraction cannot isolate a...