We describe the effects of multiple freeze and thaw cycles on the sensitivity of the immunoglobulins IgG and IgM measured by enzyme-linked immunoassays in the sera of patients with syphilis. Stored frozen sera can withstand repeated freezing and thawing cycles with a minimal detrimental effect on the sensitivity of the sera.
This study describes the effect of multiple freeze and thaw cycles on the sensitivity of immunoglobulins IgG and IgM in the sera of patients with syphilis.
From the Division of STD Prevention, Centers for Disease Control and Prevention, Atlanta, GA.
Conflict of interest: None declared.
Correspondence: Arnold R. Castro, PhD, Centers for Disease Control and Prevention Atlanta, GA 30333. E-mail: firstname.lastname@example.org.
Received for publication June 6, 2013, and accepted August 23, 2013.