What is the purpose of using a 4°C incubation step during an indirect antiglobulin test in blood grouping and crossmatching?

A To enhance the reactivity of IgG antibodies ✓
B To reduce the reactivity of IgM antibodies
C To increase the sensitivity of the test for detecting complement-binding antibodies
D To decrease the risk of false-positive results due to cold agglutinins

Explanation

The 4°C incubation step is used to enhance the reactivity of IgG antibodies, which are more active at lower temperatures, allowing for better detection of these antibodies in the indirect antiglobulin test.

Source

Technical Manual of the American Association of Blood Banks
Hematology Hematology: Blood Grouping and Crossmatching Hematology: Blood Grouping and Crossmatching Medium MEDICAL Confidence: high