no transductants??

I thought I had a lot of KanR AmpR transductants from infection of the ppdD::lacZ strain (AmpR) with the P1 lysate made on the sxy::kan strain, because lots of colonies grew overnight on the Kan+Amp plates from this infection but not from mock-infected cells. But I picked 4 colonies and streaked them on various plates (Kan, Amp, Kan+Amp, Maconkey-lac) and they mostly didn't grow. Now I suspect that some ofthe plates I used may have been too old (Amp is unstable) or otherwise problematic.

My test transduction of lacY from W3110 into C600 doesn't seem to have worked either (though I did find the TTC and get cute little red colonies). And the subsequent transduction of crp::kan into the ppdD::lacZ strain doesn't seem to have worked either.

After I carefully recheck the controls I'll redo it all with fresh plates.