Coupon Codes not valid for this testing. Fasting Required: Yes 10-12 hours Lab: Quest Diagnostics Specimen: Blood Results: Average processing time 3-5 days Note: Result turnaround times are an estimate and are not guaranteed. Our reference lab may need additional time due to weather, holidays, confirmation/repeat testing, or equipment maintenance. Description: Considered the most important form in determining risk of heart disease, LDL is a type of lipoprotein that carries cholesterol in the blood. It's considered to be undesirable because it deposits excess cholesterol in walls of blood vessels and contributes to hardening of the arteries(atherosclerosis) and heart disease. In most LDL tests, the amount is calculated. In this test, the LDL is measured. Alternative Name(s): LDL Direct, Low Density Lipoprotein, DLDL, LDL Cholesterol, Direct, Cholesterol and LDL