Converting Ray Guns to LPRs...

What you should do is: If you're going to be awake and playing when the event timer counts down and we switch over to DNA strands, stop tapping aliens for the last 4 hours and 10 minutes. Then when the switchover occurs you'll have 50 aliens to tap, which will give you a head start on collecting DNA. I did that for the switchover from probes to ray guns. Instant 100 ray guns.

Unless you need those last few ray guns to complete something else...