Whenever laboratory tests are required for the release of cases or carriers, the tests shall be taken by the health officer or his representatives and shall be submitted to a public health officer or his representatives and shall be submitted to a public health laboratory approved by the State Department of Health Services. Specimens may be sent to laboratories not so approved, provided the specimens are divided and a portion of the specimens are sent to an approved laboratory. Release shall be considered on the basis of the report of the approved laboratory only.