What is the immunoglobulin present in trace amount in serum?

The immunoglobulin present in trace amounts in serum is Immunoglobulin E (IgE). It plays a crucial role in allergic reactions and responses to parasitic infections. Although it constitutes a small fraction of total serum immunoglobulins, its activity is significant in mediating hypersensitivity reactions. Elevated levels of IgE are often associated with Allergies and Asthma.