Winter is upon us here in the northern plains. With frigid temperatures, we see the greatest impacts to unspun blood samples and formalin fixed tissues.
Tissues in formalin can freeze. Subsequent freeze artifact can severely impede evaluation of tissues and obscure important features that are necessary for an accurate diagnosis. During cold winter months with subfreezing temperatures, the addition of alcohol (isopropyl, methanol or ethanol) at a mixture of 1-part alcohol to 9-parts formalin will help prevent freeze artifact.
The images below are of two similar skin tumors. The tissue on the left is severely impacted by freeze artifact while the image on the right is of a properly preserved tissue with clear histologic features. Images by H. Pecoraro.
Serum samples should always be centrifuged prior to shipment to the laboratory. Leaving blood samples unspun or “on the clot” leads to freezing and hemolysis that may effect test results, including falsely elevated analytes and false positive or negative results. For more information on proper preparation of serum, please review our Serology Test Guide.
