Cardio IQ® Direct LDL
The Cardio IQ Direct LDL test measures LDL cholesterol, often called bad cholesterol, directly in a blood serum sample using an enzymatic method.
About this test
LDL cholesterol carries cholesterol through the bloodstream and is commonly called bad cholesterol because of its association with cardiovascular risk. This version of the test measures LDL directly from a serum sample, using an enzymatic method, rather than calculating it from other lipid values.
Because it measures LDL directly, Quest lists this as a distinct product from a calculated LDL result that is derived from a standard lipid panel. A clinician may choose the direct measurement depending on the rest of the lipid picture and how the result will be used.
Test details
| Quest code | 91723 |
|---|---|
| Methodology | Enzymatic |
| Sample type | 1 mL serum |
| Collection | Quest patient service center |
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Additional details
What this test looks at
The test reports a directly measured LDL cholesterol value from a serum sample. Quest lists this specific product under the Cardio IQ name, distinguishing the direct method from a calculated LDL result.
How it's often used alongside other tests
LDL cholesterol is one of the values commonly reported together with total cholesterol, HDL cholesterol and triglycerides as part of a broader lipid evaluation, rather than being read on its own. A clinician looks at the direct LDL value in that wider context when weighing cardiovascular risk.
Order online and a physician order is included — no doctor's visit and no insurance needed. Your sample is collected at a Quest Diagnostics patient service center.
Laboratory results should always be interpreted by a licensed clinician who knows your health history. This page is information about a test, not medical advice.
Frequently asked questions
What does this test measure?
It measures LDL cholesterol, often called bad cholesterol, directly from a blood serum sample using an enzymatic method.
How is the sample collected?
Through a routine blood draw; the test uses a serum sample collected at a Quest Diagnostics patient service center.
Do I need to prepare for this test?
No preparation instructions are listed for this test, though people follow any instructions their ordering clinician provides.
How is Direct LDL different from a calculated LDL result?
This version measures LDL cholesterol directly from the serum sample rather than calculating it from other lipid values, which is why Quest lists it as its own product under the Cardio IQ name.
Can I get the Cardio IQ® Direct LDL test without a doctor's visit or insurance?
Yes. The $49 cash price includes an independent physician's order, so no referral is needed, and insurance is never involved.