Quality system essentials $($QSEs$)$ form the foundation of a quality management system. QSEs are also:

Mandated by regulatory, standard$-$setting and diccrediting agencies.

The management infrastructure that gupports the workflow of the laboratory.

A part of providing quality patient car$.$

Maintained by specifically trained supervisory personnel.

Required to have inpjf from patient advocates.

$1$ and $A.$

$2,3$ and $5.$

$2,3$ and $4.$

$1,2$ and $3.$