The serum was tested negative for HBsAg and for antibodies against HIV 1, HIV-2 and HCV. Blood from a healthy donor (MBL genotype B/B without promoter defects) was collected in flasks without anticoagulant and allowed to clot. Serum was collected after centrifugation and pooled. After mixing, 1-ml aliquots of the serum was pipetted into 1-ml cryotubes. The material was frozen at -20°C.However, as no test method can offer complete security that infectious agents are absent, the calibrators and patients’ specimens should be handled at Biosafety Level 2 as recommended for any potentially infectious human serum or blood specimen in the CDC/NIH manual “Biosafety In Microbiology and Biomedical Laboratories”, 1999. Solutions containing human serum should be treated as potentially infectious and handled accordingly.
Form
Frozen, undiluted human serum
Storage
-20°C
Background
Human MBL is an opsonin, which activates the complement system on binding to microbial polysaccharides. Plasma concentrations of normally oligomerized MBL range from 0 to 7000 ng/ml and may be below 50 ng/ml in up to 12% of healthy Caucasian blood donors. Low plasma concentrations may be associated with an inherited opsonin defect. MBL from donors of B/B genotype is poorly oligomerized and gives low readings in MBL assays selective for oligomerized MBL.