Personal
Professional
Research
Personal Professional Research Sign Up Login Pro Login
Research Carnitine, Free
Immune System

Carnitine, Free

Optimal Result: 19 - 48 umol/L.

Carnitine is a compound in the body that helps your body digest fats for energy. A carnitine deficiency is related to a number of different medical problems. A carnitine total and free plasma test is a blood test that measures the amount of carnitine in the blood. It examines that amount of usable, or free, carnitine and compares it with the total amount of carnitine.

The analysis of carnitines is indicated in people who exhibit the following:

- failure to thrive,

- hypotonia,

- chronic muscle weakness,

- cardiomyopathy,

- intermittent episodes of weakness and encephalopathy,

- renal Fanconi's syndrome,

- hypoglycemic episodes,

- metabolic acidosis,

- or hypoketotic dicarboxylic acidurias.

------------------

Reference Ranges:

Carnitine is a quaternary, water-soluble ammonia compound biosynthesized from lysine and arginine. It serves as a mechanism for transport of long-chain fatty acids from the cytoplasm across the inner mitochondrial membrane and into the mitochondrial matrix, the site of b-oxidation of fatty acids for energy generation.

The reference range of carnitine depends on the laboratory being used;

Reference Range of Carnitine at a Single Laboratory

Age Range

Serum Free Carnitine (µmol/L)

Serum Total Carnitine (µmol/L)

Neonate

26-76

35-102

Child

41.4±10.4*

56.2±11.4*

Adolescent female

39.3±8.1*

53.2±8.9*

Adolescent male

39.6±9.3*

53.5±10.5*

Adult female

19.3-53.9**

28.1-66.4**

Adult male

38.8-69.5

44.2-79.3

*Mean ± standard deviation (SD)

**95% confidence interval (CI)

Quest Laboratories reports the reference range of total carnitine as follows:

  • Men: 30-70 μmol/L

  • Women: 25-58 μmol/L

  • Male children (age ≤17 years): 32-62 μmol/L

  • Female children (age ≤17 years): 28-59 μmol/L

Quest Laboratories reports the reference range of free carnitine as follows:

  • Men: 23-59 μmol/L

  • Women: 19-48 μmol/L

  • Male children (age ≤17 years): 25-54 μmol/L

  • Female children (age ≤17 years): 19-51 μmol/L

The University of California San Francisco Laboratory reports the normal values of free and total carnitine in adults as 18-69 μmol/L and 20-71 μmol/L, respectively.

Chace et al (2003) examined free and total carnitine levels in newborns. The reference ranges depended both on technique used (radioenzyme vs tandem mass spectroscopy) and the sample type (whole blood vs serum).

Variations in the ratio of free to total carnitine may also be important; typically, normal is reported as 0.1-0.4.

References:

Minkler PE, Stoll MS, Ingalls ST, Kerner J, Hoppel CL. Validated Method for the Quantification of Free and Total Carnitine, Butyrobetaine, and Acylcarnitines in Biological Samples. Anal Chem. 2015 Sep 1. 87 (17):8994-9001. [QxMD MEDLINE Link].

Belay B, Esteban-Cruciani N, Walsh CA, Kaskel FJ. The use of levo-carnitine in children with renal disease: a review and a call for future studies. Pediatr Nephrol. 2006 Mar. 21(3):308-17. [QxMD MEDLINE Link].

Quest Diagnostics. Available at http://www.questdiagnostics.com/testcenter/%20BUOrderInfo.action?tc=5800&labCode=AMD. 

Chace DH, Pons R, Chiriboga CA, et al. Neonatal blood carnitine concentrations: normative data by electrospray tandem mass spectometry. Pediatr Res. 2003 May. 53(5):823-9. [QxMD MEDLINE Link].

Stanley CA. Carnitine deficiency disorders in children. Ann N Y Acad Sci. 2004 Nov. 1033:42-51. [QxMD MEDLINE Link].

Reuter SE, Evans AM. Carnitine and acylcarnitines: pharmacokinetic, pharmacological and clinical aspects. Clin Pharmacokinet. 2012 Sep 1. 51(9):553-72. [QxMD MEDLINE Link].

Longo N, Amat di San Filippo C, Pasquali M. Disorders of carnitine transport and the carnitine cycle. Am J Med Genet C Semin Med Genet. 2006 May 15. 142C(2):77-85. [QxMD MEDLINE Link]. [Full Text].

Dahash BA, Sankararaman S. Carnitine Deficiency. StatPearls. 2022 Jan. [QxMD MEDLINE Link]. [Full Text].

Santra S, Hendriksz C. How to use acylcarnitine profiles to help diagnose inborn errors of metabolism. Arch Dis Child Educ Pract Ed. 2010 Oct. 95(5):151-6. [QxMD MEDLINE Link].

Scaglia F. Carnitine Deficiency. Medscape Drugs & Diseases. Updated 2019 Dec 13. [Full Text].

Magoulas PL, El-Hattab AW. Systemic primary carnitine deficiency: an overview of clinical manifestations, diagnosis, and management. Orphanet J Rare Dis. 2012 Sep 18. 7:68. [QxMD MEDLINE Link]. [Full Text].

Tein I. Metabolic myopathies. Swaiman KF, Ashwal S, Ferriero DM. Swaiman’s Pediatric Neurology Principles and Practice. 5th ed. Schor NF: Elsevier Sanders; 2012. 1627-40.

Crefcoeur LL, Visser G, Ferdinandusse S, Wijburg FA, Langeveld M, Sjouke B. Clinical characteristics of primary carnitine deficiency: A structured review using a case-by-case approach. J Inherit Metab Dis. 2022 May. 45 (3):386-405. [QxMD MEDLINE Link]. [Full Text].

Berardo A, DiMauro S, Hirano M. A diagnostic algorithm for metabolic myopathies. Curr Neurol Neurosci Rep. 2010 Mar. 10(2):118-26. [QxMD MEDLINE Link]. [Full Text].

Bernardini I, Rizzo WB, Dalakas M, Bernar J, Gahl WA. Plasma and muscle free carnitine deficiency due to renal Fanconi syndrome. J Clin Invest. 1985 Apr. 75(4):1124-30. [QxMD MEDLINE Link]. [Full Text].

Gahl WA, Bernardini I, Dalakas M, et al. Oral carnitine therapy in children with cystinosis and renal Fanconi syndrome. J Clin Invest. 1988 Feb. 81(2):549-60. [QxMD MEDLINE Link]. [Full Text].

Determination of Free and Total Carnitine and Choline in Infant Formulas and Adult Nutritional Products by UHPLC-MS/MS: Single-Laboratory Validation, First Action 2014.04. J AOAC Int. 2015 Jun 24. [QxMD MEDLINE Link].

El-Hattab AW. Systemic Primary Carnitine Deficiency. 1993. [QxMD MEDLINE Link].

Rinaldo P, Cowan TM, Matern D. Acylcarnitine profile analysis. Genet Med. 2008 Feb. 10(2):151-6. [QxMD MEDLINE Link].

Dietzen DJ, Rinaldo P, Whitley RJ, et al. National academy of clinical biochemistry laboratory medicine practice guidelines: follow-up testing for metabolic disease identified by expanded newborn screening using tandem mass spectrometry; executive summary. Clin Chem. 2009 Sep. 55(9):1615-26. [QxMD MEDLINE Link].

Johns Hopkins University Clinical Lab.

National Newborn Screening Status Report 2012. 

Stanley CA. Carnitine disorders. Adv Pediatr. 1995. 42:209-42. [QxMD MEDLINE Link].

Mamedov I, Zolkina I, Nikolaeva E, Glagovsky P, Sukhorukov V. Carnitine insufficiency in children with inborn errors of metabolism: prevalence and treatment efficacy. J Pediatr Endocrinol Metab. 2015 Jul 18. [QxMD MEDLINE Link].

Sgambat K, Moudgil A. Carnitine deficiency in children receiving continuous renal replacement therapy. Hemodial Int. 2015 Aug 11. [QxMD MEDLINE Link].

What does it mean if your Carnitine, Free result is too high?

Carnitine, specifically in its free form, is a biologically essential quaternary ammonium compound that plays a pivotal role in the metabolism of fatty acids within the mitochondria of cells. Free carnitine acts as a critical transporter, facilitating the movement of long-chain fatty acids from the cytosol into the mitochondrial matrix, where these fatty acids undergo β-oxidation to generate adenosine triphosphate (ATP), the cell's primary energy currency.

This process is vital for energy production, especially in metabolically active tissues such as the heart, skeletal muscles, and liver. The body synthesizes carnitine from the amino acids lysine and methionine, with its synthesis and regulation involving several enzymes and vitamin C as a cofactor, indicating a complex biochemical pathway that underscores its importance in cellular metabolism.

Elevated levels of free carnitine in the body could indicate a variety of conditions but primarily suggest an increased availability or intake of carnitine, either through diet or supplementation. It may also reflect metabolic differences or inefficiencies in how the body uses carnitine, such as in certain liver disorders where carnitine is not utilized properly, leading to its accumulation in the blood. In some cases, high carnitine levels can be a marker of improved carnitine synthesis or decreased usage by the body's tissues, especially if there are underlying metabolic conditions affecting energy production. However, elevated carnitine levels are relatively uncommon and usually not a cause for concern unless accompanied by other symptoms or diagnosed conditions, making it important to consult healthcare professionals for accurate diagnosis and interpretation.

What does it mean if your Carnitine, Free result is too low?

Primary carnitine deficiency is caused by an autosomal-recessive defect in the SLC22A5 gene, resulting in a lack of OCTN2, which is a high-affinity carnitine-uptake transporter expressed in muscle, kidney, and heart.

Laboratory values in primary carnitine deficiency show markedly decreased free and total carnitine levels, since 90-95% of filtered carnitine is lost in the urine. Analysis of urine organic acids, serum amino acids, and acylcarnitine panels can be used to distinguish this condition from other causes of carnitine deficiency.

Individuals with primary carnitine deficiency usually present with cardiomyopathy and skeletal weakness or with episodic hypoketotic hypoglycemia and encephalopathy when stressed at around age 2-4 years. This results from the inability to oxidize fatty acids and generate ketones to provide energy during catabolic states. The disorder is fatal without treatment, but supplementation with oral carnitine results in elevated carnitine levels and prevents progression of the disease. 

A literature review by Crefcoeur et al found that in individuals with primary carnitine deficiency, the most prevalent symptoms were cardiac (23.8% of patients), with cardiomyopathy being the predominant manifestation of these. Neurologic, hepatic, and metabolic symptoms developed in 7.1%, 8.4%, and 9.2% of persons with primary deficiency and occurred most often in early childhood. The condition was asymptomatic in 55.1% of patients with primary deficiency.

Carnitine-acylcarnitine translocase deficiency (CACT) typically presents in an autosomal-recessive fashion with seizures, apnea, and an irregular heart beat in the neonatal period (although presentation can occur as late as age 15 months) and results from mutations in the CACT protein (SLC25A20 gene), a carnitine-acylcarnitine exchanger on the inner mitochondrial membrane. Crisis is triggered by fasting, viral illness, or stress (an in other fatty-acid disorders). In addition to low carnitine levels, laboratory studies also show hypoketotic hypoglycemia; elevated levels of ammonia, creatine kinase (CK), liver enzymes, and long-chain acylcarnitines in the blood; and dicarboxylic aciduria in urinary organic acids. CACT is treated with frequent feedings of carbohydrates, medium-chain triglycerides, and carnitine.

The autosomal-recessive disorder carnitine palmitoyltransferase 2 (CPT-2) deficiency is also characterized by low carnitine levels. The CPT-2 protein is essential for removing carnitine from long-chain fatty acids after translocation into the mitochondrial matrix is and thus essential for fatty acid oxidation. Although it typically presents as a myopathy in adolescents or adults, CPT-2 deficiency can also present as severe fatal neonatal and hepatocardiomuscular infantile forms. The difference in presentation relates to the amount of residual function (genotype-phenotype correlation).

Neonates with CPT-2 deficiency present within days of birth with encephalopathy, cardiomegaly, hepatomegaly, seizures, cardiac arrhythmias, and respiratory distress, and the condition is rapidly fatal. The infantile form presents between ages 6 and 24 months as episodes of encephalopathy, liver failure, seizures, hypoketotic hypoglycemia, metabolic acidosis, elevated CK levels, reversible hepatomegaly, and, in some cases, cardiomyopathy and arrhythmias, precipitated by infection, fasting, or fever.

The adolescent and adult form of CPT-2 deficiency presents with myopathic pain precipitated by exercise, cold, fever, or prolonged fasting and may be associated with myoglobinuria and kidney damage/failure.

Elevated long-chain acylcarnitine levels are detected in all forms of CPT-2 deficiency, and neonatal screening can be useful in determining the cause of death in the neonatal form.

Secondary carnitine deficiency can result from numerous conditions, such as chronic renal failure, end-stage renal disease, renal Fanconi syndrome, Lowe syndrome, cystinosis, and valproate therapy, all of which cause impaired carnitine reuptake from the kidneys. Carnitine-free diets (such as in those receiving intravenous nutrition), organic acidurias, and urea-cycle defects can also cause deficiency. 

Transient falsely low carnitine levels have been reported in infants born to mothers with primary carnitine deficiency.

Frequently asked questions

Healthmatters is a highly-personalized health dashboard.

Instead of searching for your lab results in different places or tracking them down from different providers, Healthmatters houses, organizes, and interprets them all in one central location.

With a Healthmatters account, you can dive into the details of each biomarker and gain insights into the meaning behind your medical test data, anytime, anywhere.

For our professional users, Healthmatters provides intuitive tools that not only streamline analysis but also save valuable time when delving into your client's lab report history.

Healthmatters.io personal account provides in-depth research on 4000+ biomarkers, including information and suggestions for test panels such as, but not limited to:

  • The GI Effects® Comprehensive Stool Profile,
  • GI-MAP,
  • The NutrEval FMV®,
  • The ION Profile,
  • Amino Acids Profile,
  • Dried Urine Test for Comprehensive Hormones (DUTCH),
  • Organic Acids Test,
  • Organix Comprehensive Profile,
  • Toxic Metals,
  • Complete Blood Count (CBC),
  • Metabolic panel,
  • Thyroid panel,
  • Lipid Panel,
  • Urinalysis,
  • And many, many more.

You can combine all test reports inside your Healthmatters account and keep them in one place. It gives you an excellent overview of all your health data. Once you retest, you can add new results and compare them.

If you are still determining whether Healthmatters support your lab results, the rule is that if you can test it, you can upload it to Healthmatters.

While we work with many popular labs, we welcome reports from lots of other places too.

It's as simple as this: if you can get a test done, you can upload it to Healthmatters and we can interpret results from any lab out there. If laboratories can analyze it, we can interpret it.

If you’re on the hunt for a specific biomarker, contact us and we'll add it to our database. Anything from blood, urine, saliva, or stool can be uploaded, understood, and tracked with your Healthmatters account.

There are two ways to add your test reports to your Healthmatters account. One option is to input the data using the data entry forms. The other method is to utilize our "Data entry service."

Our data entry forms offer an easy, fast, and free way for you to input the reports yourself. Self-entry allows you to add an unlimited number of reports at no cost. We make the self-entry process user-friendly, providing dozens of templates that pre-populate the most popular laboratory panels and offering instant feedback on entered values.

For those who prefer assistance, we offer a "Data entry service" to help you input your data. Simply attach an image or file of your lab test results, and a qualified team member from our data entry team will add the results for you.

We support various file types, including PDFs, JPGs, or Excel. This service is particularly useful if you have many reports to upload or if you're too busy to handle the data entry yourself.

Our special data entry service makes it easy to add your results to your private dashboard. Just attach an image or a file of your lab test results, and our skilled data entry team will do the work for you. It's all done by humans, ensuring that your data is entered accurately and with personal care for each client.

Depending on your account, the data entry service can be included for free or come at an additional cost of $15 per report.

For users on the Complete monthly plan, the first report is entered free of charge, and each additional report incurs a fee of $15.

Unlimited account holders enjoy the entry of ten reports without charge. Subsequent reports are subject to a $15 fee per report.

Additionally, users on the Complete plan can upgrade to a yearly subscription from the account settings. The annual subscription includes a data entry service for five reports.

The Unlimited plan is a one-time purchase for $250, and it covers your account for a lifetime with no additional payments.

For the Complete plan, the cost is $15 per month. You have the flexibility to cancel it anytime through your account settings, ensuring no further payments. To avoid charges, remember to cancel at least a day before the renewal date. Once canceled, the subscription remains active until the end of the current billing cycle.

Additionally, you can upgrade to the yearly Advanced plan from within your account. The annual cost is $79, and it comes with a data entry service for five reports.

You can always upgrade to a lifetime version with a prorated price from a monthly or yearly subscription.

Simply log in and navigate to your account settings to cancel your subscription. Scroll down to locate the 'Cancel' button at the bottom of the page. Ensure you cancel at least one day before the renewal date to prevent any charges. Once cancellation is requested, the subscription remains active until the conclusion of the current billing cycle.

Our goal has been to make your Healthmatters account as intuitive as possible.

We’ve crafted multiple ways for you to navigate your data, whether you're glancing at a single report or delving into your historical test reports.

1. Graph View:

Dive into a visual journey with our biomarker graphs, showcasing over 40 data points. Combining years of results unveils trends, empowering you to make informed decisions. Our visualization tools make it a breeze to compare and understand changes over time, even if your results are from different labs. A search function and filters simplify the exploration of extensive data, allowing you to focus on what needs attention.

2. All Tests View

Explore neatly organized reports on a timeline, highlighting crucial details like dates, critical results, and lab/panel names. Each report opens up to reveal in-depth descriptions and additional recommendations for each biomarker. The history of previous results is just a click away, and you can download a comprehensive report for deeper insights. Color-coded and user-friendly, it's designed for easy reading, understanding, and navigation.

3. Table View:

For a holistic view of all biomarkers side by side, our table view is your go-to. Results are neatly displayed in a categorized and dated table, ideal for those with an extensive test history. Utilize sorting, filters, and color-coding to enhance your analysis and gain extra insights.

Yes, you can download information from your account. We can compile your labs into a CSV file. To download all your labs, you can go to Account Settings, and at the bottom of the page, you will find a link to download your information.

Yes, you can print your report. To do so, navigate to "All tests" and open the report you wish to print. You'll find a print button in the right corner of the report. Click on it, and your browser's print window will open. If you prefer to print in a bigger typeface, adjust the scale using the print window settings.

Yes, you can! We highly recommend activating Two-Factor Authentication (2FA) for your account. To do so, please navigate to the "Profile and Security" section of your account, where you will find instructions for activating 2FA.

Yes, you can. When entering values for the biomarker, you will see an "Edit Range" button. Click this button, and you'll have the option to enter a custom range.

A personal account is all about keeping your own lab test results in check. It's just for you and your personal use.

The professional account is designed for health professionals who wish to track and organize their clients' laboratory results.

To learn more about Healthmatters Pro, please refer to the professional page.

Yes, you can! Simply go to the "Invite Doctor" section, enter your doctor’s email address, and send the invitation. Your doctor will receive an email with secure access to view your results. You can revoke this access at any time. All shared information is securely encrypted and protected for your privacy.
Yes, you can! Go to the Graph view or Spreadsheet view. In the top-right corner, click "Export to Excel," and the file will be downloaded to your device.

Use promo code to save 10% off any plan.


We implement proven measures to keep your data safe.

At HealthMatters, we're committed to maintaining the security and confidentiality of your personal information. We've put industry-leading security standards in place to help protect against the loss, misuse, or alteration of the information under our control. We use procedural, physical, and electronic security methods designed to prevent unauthorized people from getting access to this information. Our internal code of conduct adds additional privacy protection. All data is backed up multiple times a day and encrypted using SSL certificates. See our Privacy Policy for more details.

Navigate to Immune System

Popular search

14.3.3 ETA PROTEIN, 21-Hydroxylase Antibody, Acetylcholine Receptor (AChR) Antibody, Activated partial thromboplastin time (APTT), Alpha 2-Macroglobulins, Qn, Alpha Melanocyte Stimulating Hormone, ANA SCREEN A, ANA SCREEN B, ANA SCREEN, IFA, ANA Screen, IFA (Positive, Negative), ANA titer, Anti-C1Q Ab, IgG (RDL), Anti-DBL-Strand DNA Ab, Anti-dsDNA (Double-stranded) Ab by Farr method (RDL), Anti-dsDNA ab (Farr Assay), Anti-IgE, ANTI-RNP (CU), Anti-Smith Antibody, Anticardiolipin Ab,IgA,Qn, Anticardiolipin Ab,IgG,Qn, Anticardiolipin Ab,IgM,Qn, Antinuclear Ab, HEp-2 Substrate, S, Antinuclear Antibodies (ANA) Screen, Reflex ANA IFA dsDNA Antibodies, Antinuclear Antibodies Direct (ANA Direct), Antiphosphatidylserine IgA, Antiphosphatidylserine IgG, Antiphosphatidylserine IgM, Antithrombin Activity (ATIII), Antithrombin III activity, Baski sleepy, Bordetella Pertussis Toxin (PT) IgG Antibody (IA), C1 Esterase Inhibitor, Func, C1 Esterase Inhibitor, Serum, C3A Desarg Fragment, C4a Level by RIA, CARDIOLIPIN AB (IGA), CARDIOLIPIN AB (IGG), CARDIOLIPIN AB (IGM), Carnitine Esters, CARNITINE, ESTERS, Carnitine, Free, Carnitine, Total, CCP Antibodies IgG/IgA, Centromere, Chromatin, Coccidioides Ab by CF, Coccidioides Ab, IgG, EIA, Coccidioides Ab, IgM, EIA, Complement C1q, Quantitative, Complement C3, Complement C3a, Complement C4, Serum, Complement C4a, Complement Component C1Q, Complement, Total (CH50), Complement, Total (CH50), Quest Diagnostics, Cyclic Citrullinated Peptide Antibody, Cysticercosis (Taenia solium), Dilute Russell's viper venom time (dRVVT), Diphtheria Antitoxoid Antibody, DNA AB Double Stranded Titer, DNA Double-Stranded Ab, IgG, dRVVT Confirm, DRVVT SCREEN, dRVVT Screen Ratio, ds-DNA Antibody, IgG, dsDNA, ENA Screen, ENA to Smith (Sm) Antibody, ENA-6 Reflexed, Eosinophil Cationic Protein (ECP), Epidermal Growth Factor (EGF), Erythrocyte Sedimentation Rate (ESR), Esterified/Free Ratio, F004-IgE Wheat, Free Kappa Lt Chains, Serum, Free Lambda Lt Chains, Serum, Ganglioside Antibodies - GM1 (IgG), Ganglioside Antibodies - GM1 (IgM), Ganglioside Antibodies - GQ1b (IgG), Gastrin, GlycA, Haemophilus Influenzae Type B Antibody (IgG), Helicobacter pylori Abs, Serum, Hemoglobin A2 (Quant), Hexagonal Phase Phospholipid, HISTAMINE RELEASE (CHRONIC URTICARIA), Histamine, Plasma, Histamine, Whole Blood, Histone, HLA-B27 (Human Leukocyte Antigen B27), Human Transforming Growth Factor Beta 1 (TGF-b1), IGE ANTIBODY (ANTI IGE IGG), Immature Grans (Abs), Immature Granulocytes (%), Immunofixation Result, Serum, Immunoglobulin A, Qn, Serum, Immunoglobulin D, Quant, Serum, Immunoglobulin E, Immunoglobulin E, Total, Immunoglobulin G, Qn, Serum, Immunoglobulin M, Qn, Serum, INFg, Influenza Type A Antibody Serum, Influenza Type B Antibody Serum, Interleukin-2, Serum, Interleukin-6, Jo 1 Antibodies, IgG, Serum, JO-1, Kappa/Lambda Ratio, Serum, Liver Kidney Mic IgG, Liver-Kidney Microsomal Antibodies, Lupus Anticoagulant, Lysozyme, Serum, Mannose Binding Lectin (MBL), Measles Antibodies, IgG, Monocyte Chemotactic Protein-1 (MCP-1), Mumps Abs, IgG, PEP A2Glob, PHOSPHATIDYLETHANOLAMINE AB (IGA), PHOSPHATIDYLETHANOLAMINE AB (IGG), PHOSPHATIDYLETHANOLAMINE AB (IGM), PHOSPHATIDYLSERINE AB (IGA), PHOSPHATIDYLSERINE AB (IGG), PHOSPHATIDYLSERINE AB (IGM), Plasminogen Activator Inhibitor (PAI-1) AG, Procalcitonin, Proliferating Cell Nuclear Antigen (PCNA), Prothrombin Fragment 1.2, Prothrombin Time (PT), Prothrombin Time (PT) INR, QUANTIFERON® -TB GOLD PLUS, 1 TUBE, RA Latex Turbid, RATIO (CBA/VW AG), Reptilase Clotting Time, Reptilase Time, RF, IgA by EIA (RDL), RF, IgG by EIA (RDL), RF, IgM by EIA (RDL), Rheumatoid factor (RF), Rheumatoid Factor IgA, Rheumatoid Factor IgG, Rheumatoid Factor IgM, Ristocetin Cofactor, RNA Polymerase III Antibodies, RNP/Sm, Ro-52kD Antibody, Schistosoma IgG, Scl-70, Sed Rate by Modified Westergren, Semi-Quant RF, SICKLE CELL SCRN, Sirolimus, Whole Blood, Sm, SM/RNP Antibody, Smith/RNP (ENA) Ab, IGG, Smooth Muscle Abs, IFA, Ss-B/La Ab Igg, SSA, SSA-52 (Ro52) (ENA) Antibody, IgG, SSA-60 (Ro60) (ENA) Antibody, IgG, SSB, ssDNA, Tacrolimus, Highly Sensitive, LC/MS/MS, Tacrolimus, Whole Blood, TB1-NIL, TB2-NIL, Tetanus Antitoxoid IgG Ab, TGF-b1, Thrombin time, Thrombin-Antithrombin TAT, TNFb, Trans. Growth Fact. beta 1, Transforming Growth Factor beta, Plasma, Tryptase, Tumor Necrosis Factor, Varicella-Zoster Virus (VZV) DNA, Qualitative, Real-Time PCR, VEGF, Plasma, VEGF, Serum, von Willebrand Factor Activity, Von Willebrand Factor Antigen (vWF), VW Activity/VW Antigen Ratio, VWF: COLLAGEN BINDING