Interlibrary loan in primary access libraries: challenging the traditional view.

Introduction: Primary access libraries serve as the foundation of the National Network of Libraries of Medicine (NN/LM) interlibrary loan (ILL) hierarchy, yet few published reports directly address the important role these libraries play in the ILL system. This may reflect the traditional view that small, primary access libraries are largely users of ILL, rather than important contributors to the effectiveness and efficiency of the national ILL system.

Objective: This study was undertaken to test several commonly held beliefs regarding ILL system use by primary access libraries.

The molecular weight of aspermatogenic antigen as determined by equilibrium ultracentrifugation.

The extraction of antigen from testis and sperm is described. This antigen, when administered in microgram amounts in a single injection, induces aspermatogenesis in 100% of guinea pigs so treated. The deletion of the seminiferous cell line is specific (no cross-reactions) and provides a tool for investigating inhibition of cell replication as well as reproductive control.