Government source for the detection of ricin and SEB. The addition of lactose at concentrations up to 100mMin the buffer suppliedwith the LFDs failed to eliminate the false positives observed with wheat lectin. However, no false positives were observed upon preparing the samples in 50% PBSTM. Substitution of the LFD buffer with 50% PBSTM increased the LOD from 2.5 ng/mL to 10 ng/mL; the ricin from Vector laboratories displayed a slightly greater increase in the LOD with 50% PBSTM and slightly lower sensitivity than the ricin used to spike the cosmetics.