Test Catalog

Test Id : SDLDL

Small Dense Low Density Lipoprotein Cholesterol, Serum

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in risk management of lipoprotein disorders associated with cardiovascular disease when used in conjunction with other lipid measurements and clinical evaluation

Method Name
A short description of the method used to perform the test

Enzymatic Colorimetric

NY State Available
Indicates the status of NY State approval and if the test is orderable for NY State clients.


Reporting Name
Lists a shorter or abbreviated version of the Published Name for a test

Small Dense LDL Cholesterol, S

Lists additional common names for a test, as an aid in searching

Small dense LDL Cholesterol

sdLDL cholesterol

Specimen Type
Describes the specimen type validated for testing


Specimen Required
Defines the optimal specimen required to perform the test and the preferred volume to complete testing

Patient Preparation: Fasting: Overnight (8-12 hours)

Collection Container/Tube:

Preferred: Serum gel

Acceptable: Red top

Submission Container/Tube: Plastic vial

Specimen Volume: 1 mL

Collection Instructions:

1. Centrifuge and aliquot serum into a plastic vial.

2. Send frozen.


If not ordering electronically, complete, print, and send a Cardiovascular Test Request (T724) with the specimen.

Specimen Minimum Volume
Defines the amount of sample necessary to provide a clinically relevant result as determined by the testing laboratory. The minimum volume is sufficient for one attempt at testing.

0.5 mL

Reject Due To
Identifies specimen types and conditions that may cause the specimen to be rejected

Gross hemolysis Reject
Thawing** Cold OK; Warm reject
Gross lipemia Reject
Gross icterus Reject

Specimen Stability Information
Provides a description of the temperatures required to transport a specimen to the performing laboratory, alternate acceptable temperatures are also included

Specimen Type Temperature Time Special Container
Serum Frozen (preferred) 30 days
Refrigerated 72 hours
Ambient 8 hours

Useful For
Suggests clinical disorders or settings where the test may be helpful

Aiding in risk management of lipoprotein disorders associated with cardiovascular disease when used in conjunction with other lipid measurements and clinical evaluation

Clinical Information
Discusses physiology, pathophysiology, and general clinical aspects, as they relate to a laboratory test

Low-density lipoprotein cholesterol (LDL-C) has long been known to be causally associated with atherosclerotic plaque development and progression and is the main target of lowering cardiovascular disease risk. Subfractions of LDL, particularly the concentration of small dense LDL-C, have been shown to also be associated with increased risk for coronary heart disease (CHD). It is thought that the smaller particles are especially pro-atherogenic given their higher probability to transverse the arterial wall and a longer circulating half-life, likely from a lower binding affinity to the LDL receptor. Several epidemiological and pathological studies have reported an association between the concentration of small dense LDL-C and CHD. Results should be used in conjunction with the patient's medical history and other laboratory and clinical results.

Reference Values
Describes reference intervals and additional information for interpretation of test results. May include intervals based on age and sex when appropriate. Intervals are Mayo-derived, unless otherwise designated. If an interpretive report is provided, the reference value field will state this.

> or =18 years: < 50 mg/dL

Reference values have not been established for patients who are <18 years of age.

Provides information to assist in interpretation of the test results

Results of 50 mg/dL or greater indicate increased risk of incident coronary heart disease (CHD) (myocardial infarction, fatal CHD, or cardiac procedure).

Discusses conditions that may cause diagnostic confusion, including improper specimen collection and handling, inappropriate test selection, and interfering substances

Results should not be used as a replacement for low-density lipoprotein cholesterol and should not be used in risk calculators.


In very rare cases, gammopathy, in particular type IgM (Waldenstrom macroglobulinemia), may cause unreliable results.

Clinical Reference
Recommendations for in-depth reading of a clinical nature

1. Tsai MY, Steffen BT, Guan W, et al. New automated assay of small dense low-density lipoprotein cholesterol identifies risk of coronary heart disease: the multi-ethnic study of atherosclerosis. Arterioscler Thromb Vasc Biol. 2014;34(1):196-201. doi:10.1161/ATVBAHA.113.302401

2. Hoogeveen RC, Gaubatz JW, Sun W, et al. Small dense low-density lipoprotein-cholesterol concentrations predict risk for coronary heart disease: the atherosclerosis riskiIn ommunities (ARIC) study. Arterioscler Thromb Vasc Biol. 2014;34(5):1069-1077. doi:10.1161/ATVBAHA.114.303284

3. Hirano T, Ito Y, Yoshino G. Measurement of small dense low-density lipoprotein particles. J Atheroscler Thromb 2005;12(2):67-72

4. Ogita K, Ai M, Tanaka A, et al. Circadian rhythm of serum concentration of small dense low-density lipoprotein cholesterol. Clin Chim Acta. 2007 Feb;376(1-2):96-100

5. Balling M, Nordestgaard BG, Langsted A, Varbo A, Kamstrup PR, Afzal S. Small dense low-density lipoprotein cholesterol predicts atherosclerotic cardiovascular disease in the copenhagen general population study. J Am Coll Cardiol. 2020;75(22):2873-2875. doi:10.1016/j.jacc.2020.03.072

Method Description
Describes how the test is performed and provides a method-specific reference

This test system is a multi-step method measured on automated chemistry analyzers. The assay consists of two steps and is based on the technique of using well-characterized surfactants and enzymes that selectively react with certain groups of lipoproteins.(Package insert: Small dense LDL Seiken. Roche Diagnostics; V 2.0, 11/2021)

PDF Report
Indicates whether the report includes an additional document with charts, images or other enriched information


Day(s) Performed
Outlines the days the test is performed. This field reflects the day that the sample must be in the testing laboratory to begin the testing process and includes any specimen preparation and processing time before the test is performed. Some tests are listed as continuously performed, which means that assays are performed multiple times during the day.

Monday through Sunday

Report Available
The interval of time (receipt of sample at Mayo Clinic Laboratories to results available) taking into account standard setup days and weekends. The first day is the time that it typically takes for a result to be available. The last day is the time it might take, accounting for any necessary repeated testing.

1 to 3 days

Specimen Retention Time
Outlines the length of time after testing that a specimen is kept in the laboratory before it is discarded

7 days

Performing Laboratory Location
Indicates the location of the laboratory that performs the test


Several factors determine the fee charged to perform a test. Contact your U.S. or International Regional Manager for information about establishing a fee schedule or to learn more about resources to optimize test selection.

  • Authorized users can sign in to Test Prices for detailed fee information.
  • Clients without access to Test Prices can contact Customer Service 24 hours a day, seven days a week.
  • Prospective clients should contact their account representative. For assistance, contact Customer Service.

Test Classification
Provides information regarding the medical device classification for laboratory test kits and reagents. Tests may be classified as cleared or approved by the US Food and Drug Administration (FDA) and used per manufacturer instructions, or as products that do not undergo full FDA review and approval, and are then labeled as an Analyte Specific Reagent (ASR) product.

This test has been cleared, approved, or is exempt by the US Food and Drug Administration and is used per manufacturer's instructions. Performance characteristics were verified by Mayo Clinic in a manner consistent with CLIA requirements.

CPT Code Information
Provides guidance in determining the appropriate Current Procedural Terminology (CPT) code(s) information for each test or profile. The listed CPT codes reflect Mayo Clinic Laboratories interpretation of CPT coding requirements. It is the responsibility of each laboratory to determine correct CPT codes to use for billing.

CPT codes are provided by the performing laboratory.


LOINC® Information
Provides guidance in determining the Logical Observation Identifiers Names and Codes (LOINC) values for the order and results codes of this test. LOINC values are provided by the performing laboratory.

Test Id Test Order Name Order LOINC Value
SDLDL Small Dense LDL Cholesterol, S 90364-1
Result Id Test Result Name Result LOINC Value
Applies only to results expressed in units of measure originally reported by the performing laboratory. These values do not apply to results that are converted to other units of measure.
SDLDL Small Dense LDL Cholesterol, S 90364-1

Test Setup Resources

Setup Files
Test setup information contains test file definition details to support order and result interfacing between Mayo Clinic Laboratories and your Laboratory Information System.

Excel | Pdf

Sample Reports
Normal and Abnormal sample reports are provided as references for report appearance.

Normal Reports | Abnormal Reports

SI Sample Reports
International System (SI) of Unit reports are provided for a limited number of tests. These reports are intended for international account use and are only available through MayoLINK accounts that have been defined to receive them.

SI Normal Reports | SI Abnormal Reports