A spermatozoon or spermatozoan (pl. spermatozoa), from the ancient Greek (seed) and (living being) and more commonly known as a sperm cell, is the haploid cell that is the male gamete. It joins an ovum to form a zygote. A zygote is a single cell, with a complete set of chromosomes, that normally develops into an embryo.

Amidase

• Sperm-bound amidase activity as a marker for acrosomal integrity in bull spermatozoa. PMID: 3038814

Aromatase

• a key enzyme responsible for the irreversible transformation of androgens into estrogens, is expressed in human ejaculated spermatozoa: a putative marker of motility.  PMID: 12606587

CD46

• restricted to spermatozoa and their immediate precursors in the testis. PMID: 15601919

Inhibin B

• Serum inhibin B level seems to be more accurate than serum FSH level in prediction of the presence of testicular spermatozoa in patients with nonobstructive azoospermia. PMID: 11730738

Mannitol

• an effective extracellular marker for human spermatozoa if concentrations greater than or equal to 0.3 mM are used. PMID: 6415273

Protamine 1 and 2

• suitable markers for spermatozoa because they are exclusively expressed in the haploid genome and that protamine mRNA can be detected in semen stains by the highly sensitive reverse transcriptase-polymerase chain reaction (RT-PCR). PMID: 12799737

TEPA

• A marker for use in evaluating fertilizing ability of rabbit spermatozoa in competitive fertilization. PMID: 58674