From which laboratory division would a 2-hour postprandial blood sugar (PPBS) test be ordered?

The correct choice is Chemistry, as a 2-hour postprandial blood sugar (PPBS) test falls within the scope of biochemical analysis conducted by the chemistry laboratory. This test measures the glucose levels in a patient's blood two hours after they have consumed a meal, and is particularly used to assess how well the body manages blood sugar levels.

Biochemical tests for substances like glucose, electrolytes, and enzymes are the primary focus of the chemistry department in a laboratory, which also performs tests on bodily fluids such as blood and urine. In this context, the Chemistry division is essential for understanding metabolic functions and diagnosing metabolic disorders such as diabetes.

On the other hand, the hematology division focuses on blood-related components like cells and coagulation factors, microbiology deals with infectious agents and their response to treatments, and immunology centers around the immune response and antibodies. Each of these divisions has distinct functions that do not include the analysis of glucose levels post-meal.