Children’s Hospital of Philadelphia is a global leader in pediatric diagnostics. Our Clinical Lab Outreach Testing Service offers access to some of the most advanced and esoteric testing available today. We offer one of the nation’s largest pediatric pathology programs; comprehensive genomics for rare diseases and critically ill newborns; transplant diagnostics; oncology tumor profiling and longitudinal monitoring; as well as specialized assays for inborn errors of metabolism. 

How we serve you

• 15,000+ outreach diagnostic tests performed annually across all clinical laboratories at CHOP
• 500+ hospital, health system, and biopharma partners throughout the United States and abroad who send testing to CHOP
• 250+ highly specialized lab-developed tests, including customized pediatric specific reference ranges and interpretation  

Getting started is simple

Connecting with our clinical laboratories is easy and straightforward. Whether you have questions about a diagnosis, want to send a sample, or just learn more about our specialized pediatric testing, our team is here to help.  

Here are a few key links related to our Clinical Lab Outreach Testing Services. 

• Explore our full test menu and services
• Access requisition forms to request testing at CHOP
• Review specimen requirements and shipping guidelines
• Review our clinical reference lab terms and conditions
• View our license and accreditation certificates
• Contact our laboratory experts directly for support   

Below you’ll find an overview of the type of testing our lab performs, the number of specialized tests available in each category, as well as key diagnostic tests that can guide treatment for rare and life-altering diseases and conditions.

Genomic diagnostics (testing for rare diseases)

Our Genomic Diagnostics Lab offers a comprehensive menu of assays spanning cytogenetics, arrays and genome-based sequencing to support the diagnosis, management and recurrence risk assessment for patients and families with rare conditions. Our test menu includes approximately 100 individual outreach tests.

Test spotlight

RTAG-I (rapid targeted analysis of the genome – infants) is a genome-based, next-generation sequencing assay specifically designed for critically ill infants with suspected genetic disorders. This rapid test targets a curated panel of high-priority genes associated with severe, early-onset conditions, enabling prompt identification of pathogenic variants that may explain a child’s clinical presentation.

Developed to support urgent clinical decision-making in intensive care settings, RTAG-I delivers high-yield diagnostic insights with a significantly accelerated turnaround time compared to traditional comprehensive genetic testing. The test is particularly valuable for infants with undiagnosed multi-system involvement, complex congenital anomalies, metabolic disturbances, or neurologic decline — where early intervention can have a meaningful impact on outcomes, treatment selection and family counseling.

Genomic diagnostics (germline and somatic testing for oncology)

The oncology arm of the laboratory provides comprehensive genomic profiling for pediatric tumors using advanced technologies including next-generation sequencing (NGS), fusion gene detection and liquid biopsy techniques. With 50 individualized tests, these diagnostics are designed to support precise diagnosis, inform prognosis and guide individualized treatment decisions by identifying actionable mutations and targeted therapy options. 

Test spotlight

Liquid biopsy neuroblastoma panel A is a non-invasive, next-generation sequencing (NGS) assay that analyzes tumor-derived genetic alterations in cell-free DNA. The test enables real-time, serial monitoring of a patient’s disease, and supports treatment decision-making for patients with neuroblastoma. 

RNA transcriptome profiling utilizes NGS to detect gene fusions, abnormal splicing events, and expression signatures — providing critical molecular insights that can support a cancer diagnosis, classification and therapeutic targeting.  

Comprehensive hematologic and solid tumor panels are designed specifically for pediatric oncology and integrate sequencing, copy number variation, and fusion analysis across hundreds of cancer-related genes to support accurate diagnosis and personalized treatment planning  

Metabolic and advanced diagnostics

Our Metabolic Diagnostics Laboratory uses advanced analytical platforms — including mass spectrometry and chromatography-based methods — to perform basic and comprehensive biochemical metabolite analyses. These tests are essential for identifying and monitoring a wide range of inherited and acquired metabolic disorders. 

By analyzing amino acids, organic acids, acylcarnitines and other biomarkers, the lab supports early diagnosis, guides treatment decisions and enables longitudinal monitoring of therapeutic efficacy. With 35 individual tests, the laboratory plays a critical role in CHOP’s multidisciplinary approach to managing complex metabolic conditions across the lifespan.  

Test spotlight

N-Glycan profile analysis and CDT analysis support the diagnosis of congenital disorders of glycosylation (CDGs) through glycan profiling and transferrin isoform analysis.  

Mitochondrial assays, including glutathione, ketone body, and OXPHOS profiling, assess mitochondrial function in suspected disorders. 

MPS/Oligosaccharide assays detect abnormal accumulation of glycosaminoglycans and oligosaccharides, which aid in the diagnosis of lysosomal storage and related metabolic diseases.  

Immunogenetics Laboratory

The Immunogenetics Laboratory offers 30 individualized and comprehensive tests to support immune-related and transplant medicine. Services include: 

• High-resolution HLA typing (via next-generation sequencing) for solid organ and bone marrow transplant
• Antibody detection and characterization (including donor-specific antibodies)
• Disease association studies
• Post-transplant engraftment monitoring (chimerism analysis) 

These capabilities are critical for ensuring transplant compatibility, guiding treatment for immune dysregulation and autoimmune disorders, and supporting longitudinal surveillance following transplantation. 

Test spotlight

High-resolution HLA typing is essential for accurate donor-recipient matching in solid organ and bone marrow transplantation. This test employs next generation sequencing to deliver precise, allele-level HLA results.   

HLA disease association studies detect HLA alleles associated with autoimmune and immune-mediated disorders. These insights can support diagnosis, inform treatment decisions and help predict therapeutic response. 

Immunology Laboratory

The Immunology Laboratory offers comprehensive testing to evaluate immune system integrity and function. This includes analysis of immune cell subsets, immunoglobulin quantification and detection of autoantibodies. These assays are part of 30 individual tests and support the diagnosis and ongoing management of primary immunodeficiencies, immune dysregulation syndromes and autoimmune conditions. Results help guide clinical decision-making and treatment planning across a wide range of immune-related disorders.  

Test spotlight

The proinflammatory cytokine panel quantifies key circulating cytokines involved in immune activation and offers critical insight into hyperinflammatory conditions. This panel supports the evaluation and management of disorders such as hemophagocytic lymphohistiocytosis (HLH), multi-system inflammatory syndrome in children (MIS-C), and other cytokine storm syndromes.  

Anatomic Pathology

The Anatomic Pathology Laboratory covers all areas of pediatric pathology with expertise in neuropathology, gastrointestinal pathology, hematopathology, and perinatal/placental pathology. Through 15 individual tests, this lab evaluates biopsies, resections, cytology, autopsies and placentas to deliver integrated morphologic and molecular diagnoses for pediatric disease management.    

Test spotlight

Anti-enterocyte antibody testing is a specialized assay that detects auto-antibodies directed against intestinal epithelial cells and can be used to aid in the diagnosis of autoimmune enteropathy. This test is particularly valuable in distinguishing autoimmune processes from infectious, allergic or inflammatory causes of chronic enteritis in children.

Surgical pathology consultations are offered by CHOP’s Anatomic Pathology team to provide comprehensive primary and second-opinion consultations for pediatric surgical specimens. These expert reviews — which may span tumors, biopsies and complex resections — support diagnostic accuracy, inform treatment decisions and are often sought by external hospitals that are managing rare or challenging pediatric cases.

Center for Diagnostic Innovation

CHOP’s Center for Diagnostic Innovation is a CAP- and CLIA-accredited powerhouse driving the next generation of pediatric diagnostics. Positioned at the intersection of research and clinical application, the Center for Diagnostic Innovation (CDI) specializes in the rapid development, validation and deployment of cutting-edge biomarker and esoteric tests across rare diseases, oncology and metabolic disorders.  

Through strategic collaborations with clinicians, academic researchers and biopharma partners, CDI accelerates the path from scientific discovery to clinical impact — bringing novel assays to life, enabling earlier detection, more precise diagnoses and personalized therapeutic decision-making for the most complex pediatric patients.  

Test spotlight

CNS methylation array is a cutting-edge epigenetic assay that analyzes genome-wide methylation patterns to classify central nervous system tumors with high accuracy. This test is particularly valuable in diagnostically ambiguous or histologically challenging cases and can enhance diagnostic confidence, inform treatment decisions, and support precision medicine approaches in pediatric neuro-oncology.

Methylation array for sarcoma tumors and reflex methylation array for sarcoma tumors. These assays are available for both pediatric and adult patients and provide additional molecular tools to support the diagnosis and classification of sarcomas.

The methylation array for sarcoma tumors is a genome-wide epigenetic profiling assay that evaluates DNA methylation patterns in tumor tissue to support sarcoma diagnosis and classification. By comparing a tumor's methylation signature to established sarcoma profiles, the test can help confirm WHO classifications, resolve diagnostically challenging cases, and identify molecular subgroups that may not be apparent through routine testing. The reflex array offers reanalysis of existing methylation data, providing additional diagnostic insight without requiring a new specimen in most cases.

These additions are important because sarcoma subtypes can differ significantly in prognosis, treatment approach, and clinical trial eligibility, making accurate classification critical. Used alongside surgical pathology and genomic testing such as CHOP's Comprehensive Solid Tumor Panel, methylation profiling provides an additional layer of molecular characterization that can help clarify challenging cases and support diagnostic confidence when traditional histologic and molecular findings are inconclusive.