Effect of Anticoagulants and Heat on the Detection of Tumor Necrosis Factor in Murine Blood
ARMED FORCES RADIOBIOLOGY RESEARCH INST BETHESDA MD
Pagination or Media Count:
Assays for tumor necrosis factor TNF may be inhibited by nonspecific factors present in body fluids. We found that the ability to quantitate TNF is greatly affected by blood processing methods. Mice were anesthetized by inhalation of methoxyflurane before obtaining blood by cardiac puncture. The blood from a group of mice was allowed to clot before recovery of serum. Plasmas were obtained from three other groups of mice after collection of blood into tubes containing EDTA, sodium citrate, or preservative-free heparin. The pooled serum or plasmas were spiked with rhTNF to a final concentration of 1 microns per ml aliquoted for frozen storage. The serum and plasmas were divided into heated 56 deg C for 30 min and unheated portions prior to a standard L929 cytotoxicity assay. Comparison of absorbances at 595 nm after crystal violet staining of cells revealed differences in detection of TNF in plasmas compared to serum and in heated compared to nonheated samples.
- Medicine and Medical Research