Table 1. ELISA analyses.

protein	control antibodies			anti-Gag-H antibody clones
	anti-His	anti-GST	protein specific	1B3H7	1D7D11	2H2D6	14H11G1
HERV-E (matrix)	4.010	0.155	3.141	0.136	0.143	0.130	0.129
HERV-K HML-2 (matrix)	3.948	0.142	3.183	0.140	0.145	0.144	0.176
HERV-K HML-2 (capsid)	4.187	0.135	3.143	0.140	0.133	0.131	0.148
HERV-W (matrix) GST	1.183	0.535	3.230	0.164	0.131	0.224	0.134
HERV-W (capsid)	4.193	0.154	3.020	0.131	0.186	0.126	0.157
HERV-K HML-5 (matrix)	3.242	0.136	3.500	0.131	0.980	0.127	0.130
GST	2.477	0.518	3.154	0.138	0.229	0.123	0.126
Gag-H GST	0.748	0.331	n.d.	3.951	1.531	4.237	1.373

The OD₄₀₅ values in the control antibody columns give information on the integrity of the proteins used, which are named in the first column. Antibodies used (distinguished in control and anti-Gag-H clones) are given in the headlines. Underlined values in the GST column can be considered background since the tested proteins have no GST-tag. Integrity of all proteins used is demonstrated with values above background of the anti-His antibody, of the anti-GST antibody (against the proteins with GST tag only) and of the different antibodies directed against the HERV control proteins.

Cross reactivity of the anti-Gag-H antibody clones with other HERV family proteins was also tested. Generally, values were at background level with the exception of 1D7D11 against HERV-K HML-5 (matrix), thus, we can exclude cross reactivity with the exception of 1D7D11 for HERV-K HML-5 (matrix). n.d., not done.