Folate, erythrocytes

Alternate test name

Folic Acid

Lab area

Clinical Biochemistry - General

Method and equipment

Equipment : Roche Cobas Pro e801

Method : Competition principle. Total duration of assay: 27 minutes.

▪ 1st incubation: By incubating 15 µL of sample with the folate pretreatment reagents 1 and 2, bound folate is released from endogenous folate binding proteins.

▪ 2nd incubation: By incubating the pretreated sample with the ruthenium labeled folate binding protein, a folate complex is formed, the amount of which is dependent upon the analyte concentration in the sample. ▪ 3rd incubation: After addition of streptavidin-coated microparticles and folate labeled with biotin, the unbound sites of the ruthenium labeled folate binding protein become occupied, with formation of a ruthenium labeled folate binding protein-folate biotin complex. The entire complex becomes bound to the solid phase via interaction of biotin and streptavidin.

▪ The reaction mixture is aspirated into the measuring cell where the microparticles are magnetically captured onto the surface of the electrode. Unbound substances are then removed with ProCell II M. Application of a voltage to the electrode then induces chemiluminescent emission which is measured by a photomultiplier.

▪ Results are determined via a calibration curve which is instrument specifically generated by 2‑point calibration and a master curve provided via the cobas link.

Expected turn-around time

STAT/ Urgent/ Routine: 7 Days

Specimen type

K2EDTA for RBC Folate, Protect from light

Specimen requirements

1 mL

Storage and transportation

Frozen

Special requirements

Hematocrit (HCT) value is required for calculation.

Shipping information

The Hospital for Sick Children

Rapid Response Laboratory

555 University Avenue, Room 3642

Toronto, ON

Canada

M5G 1X8

Phone: 416-813-7200

Toll Free: 1-855-381-3212

Hours: 7 days/week, 24 hours/day

Requisition

Folate, erythrocytes - requisition

Background and clinical significance

Folates are a class of vitamin compounds related to pteroylglutamic acid (PGA), which serve as cofactors
in the enzymatic transfer of single carbon units in a variety of metabolic pathways Folates are necessary for nucleic acid and mitochondrial protein synthesis, amino acid metabolism, and other cellular processes that involve single carbon transfers Because deficiencies of both vitamin B12 and folate can lead to megaloblastic (macrocytic) anemia, appropriate treatment requires differential diagnosis of the deficiency; thus, both vitamin B12 and folate values are needed.folate values reflect the second stage of negative folate balance, and more closely correlate with tissue levels and megaloblastic anemia.