What to know
- Cholesterol Reference Method Laboratory Network (CRMLN) members provide reference measurement services to laboratories and test manufacturers using CDC's standardization protocols.
- CRMLN members are encouraged to provide reference measurement services for total cholesterol, HDL-C, LDL-C, and total glycerides.
Joining the network
Cholesterol Reference Method Laboratory Network (CRMLN) members provide reference measurement services for total cholesterol, HDL-C, LDL-C, and total glycerides, to laboratories and test manufacturers globally. Network laboratories can be associated with medical schools, state health departments, and nonprofit organizations. Any laboratory desiring to become a participating member in the CRMLN needs to meet the following criteria:
- Operate and maintain the reference measurement procedures used in CDC's Standardization Programs
- Participate in the biannual CRMLN studies
- Provide certification services to the clinical and research community for the analytes used in CDC's standardization programs, in compliance with the CDC standardization protocols
- Share reference measurement procedures with other network members
Membership processes
- A candidate laboratory must submit an official request on laboratory letterhead to cdclsp@cdc.gov to apply for network membership. The request should state the analytes and reference methods the laboratory would like to provide certification services for, and documentation demonstrating their ability to perform the tasks outlined above.
- A qualified candidate laboratory must successfully pass two consecutive challenges that demonstrate its ability to meet CRMLN network performance criteria. The analytical performance criteria for CRMLN laboratories (see table below) are more stringent than those for clinical laboratories measuring patient samples. This enables CRMLN laboratories to appropriately assess the measurement accuracy and precision of tests used in patient care.
- Upon successfully passing the challenges, the laboratory acquires CRMLN membership and participates in fulfilling the network roles and responsibilities.
Questions related to membership can also be sent to cdclsp@cdc.gov.
Analytical performance criteria for CRMLN member laboratories
For each analyte, CRMLN members are evaluated for agreement with the criteria presented in the table:
| TC | LDL-C | HDL-C | |
|---|---|---|---|
| Bias1 | ≤ 1% | ≤ 2% | ≤ 1 mg/dL |
| Imprecision | ≤ 1% | ≤ 1.5% | ≤ 1 SD |
1bias to CDC reference measurement procedure
TC: Total Cholesterol
HDL-C: High Density Lipoprotein Cholesterol
LDL-C: Low Density Lipoprotein Cholesterol
Procedures for certification of manufacturers
Procedures for certification of clinical laboratories
CRMLN: For Clinical Laboratories