In Vitro Swelling of the Human Sperm Nucleus in the Presence of Sodium Dodecyl Sulphate

Abstract

The in vitro swelling of human sperm nuclei in the presence of sodium dodecyl sulphate (SDS) was studied by counting swollen sperm nuclei in a microscopic preparation and by measuring the decrease of optical density at 600 nm (OD₆₀₀). At pH 8.0 or lower, OD₆₀₀ showed a linear relationship to the sperm count. At higher pH values a fraction of the nuclei became swollen and OD₆₀₀ decreased proportionally, although the sperm count did not change in the first 2 hr. The fraction of swollen sperm nuclei increased with time and by raising the pH or temperature. The swelling occurred only in the presence of SDS and was the consequence of a binding of SDS to the hydrophobic regions of the nuclear proteins.

Key Words:

• Spermatozoa
• SDS
• Man
• Nucleus
• Decondensation.