We have recently (in the last 6 months) been having a problem where our mouse secondaries are requiring very high concentrations (1:500 gives ok results with the previous company and 1:5000 was ok with the new company, the new one used to work well with 1:20000). We also need to use 5ul on marker just to see the bands whereas before the problems started we were using 2ul with no problem and 1:2000 dilutions.
Has anyone ever seen this before? The rabbit secondaries are fine. It also seems like it would only really affect the markers.
We are using MagicMark XP.