Over 1400 HIV-1 infected individuals regularly attend the clinic at ITM. Of these, 200 patients were identified whose origin was the sub-Saharan regions of Africa where subtype A, subtype C and/or CRF02_AG isolates are prevalent. Their plasma was evaluated when they were therapy naïve or at least 6 months therapy-free for the ability to neutralize primary HIV-1 strains from the A, C and/or CRF02_AG subtypes in the 24/1/14 extended incubation phase PBMC neutralization assay. About 25% of these patients had cross-neutralizing plasma i.e. plasma which neutralized at least 50% of strains belonging to one subtype plus at least 25% of strains from a second. We next classified the best responding plasma according to the HIV subtype they preferentially neutralized: e.g. when at least three out of four of the A or C strains (or five out of six CRF02 strains) gave greater than 80% neutralization. In Table 2 this neutralization profile is shown for 20 patients whose memory B cells were interrogated. According to these criteria, four patients' plasma preferentially neutralized subtype A strains (HGL-, HGD-, HQ-and HGN plasma) and two were more specific for subtype C (HVDA and HK plasma). We did not find any patients preferentially recognizing the CRF02 strains. Three of the tested patients neutralized subtypes A and C more than CRF02 (HMB-, HJ-and HGR plasma), one was more C and CRF02 subtype specific (HMQ plasma) and finally five patients displayed broad crossneutralizing activity over all three subtypes (HU-, HP/HM/ HGM-, HE-, HY-and HMV plasma). The remaining five interrogated patients did not display this subtype specific behavior (HL-, HZ-, HGP-, HR-and HMA plasma). There is no obvious association between the subtype infecting a patient and that neutralized by his or her plasma. The patients, from whom the newly isolated mAb were obtained, are underlined in the first column. Remarkably, plasma from these patients showed a rather subtype specific neutralization profile since plasma from patient 242315 (HJ patient) neutralized mainly A and C strains, plasma from patient 314994 (HGN patient) mainly A strains and plasma from patient 529552 (HK patient) mainly C strains. In Table 3 the clinical histories of these patients are summarized.