Figure 4From: Intranasal inoculation of sows with highly pathogenic porcine reproductive and respiratory syndrome virus at mid-gestation causes transplacental infection of fetuses Immunohistochemical detection of HP-PRRSV in the fetal spleen at 7 dpi. (A, C) Negative control splenic tissue, in which mouse IgG was substituted for the primary antibody; (B) spleenic tissue from the day 60 infected group; (D) spleenic tissue from the day 90 infected group. All images are shown at ×40 magnification.Back to article page