Which of the following would be considered direct costs?

Direct costs are expenses that can be directly attributed to a specific cost center or activity, in this case, related to laboratory operations. Supplies, instrumentation, and reagents specific to tests fall into this category because they are essential materials used directly in the testing process. When a lab performs a test, the costs of these items can be directly linked to the individual tests being conducted, making them direct costs.

Other options such as administrative labor expenses, utility bills for lab operations, or depreciation of lab equipment are considered indirect costs. Administrative labor expenses cover overhead for support staff who are not directly involved in the testing process but rather in the management and administrative functions of the laboratory. Utility bills encompass general operational costs that support the facility as a whole rather than specific activities. Depreciation of lab equipment reflects the allocation of the equipment's cost over its useful life and is not directly tied to the output of specific tests. These distinctions clarify why supplies, instrumentation, and reagents are classified as direct costs.