The robot is a x,y,z motion control unit equipped with a printing head containing several printing tips. The design of the tips allows the uptake of a small volume of sample by capillarity. The tips are dipped into the samples and then moved towards the first slide where they touch the surface and deliver a small aliquot (1-5 nl) forming a dot with a diameter of ca 150 microns. One sample uptake is sufficient to print 100 slides. The tips are breifly sonicated then washed with water and dried for three cycles in between the sample takes.
Sample plates are thawed, briefly centrifuged and placed on the robot platten.
After printing, slides are allowed to dry for min 24hr in a slide box followed by 60 min at 60°C1.
Put slides in slide holder.
Soak slides with gentle agitation in staining dish:
1. 0.2% SDS for 2 min
2. 0.2% SDS for 2 min
3. ddH2O for 2 min
4. ddH2O for 2 min
5. ddH2O at 95-100°C for 2 min (DNA denaturation)
6. dry slides at 800 rpm for 5 min
7. sodium borohydride for 5 min3 (reduce free aldehydes)
8. 0.2% SDS for 1 min
9. 0.2% SDS for 1 min
10. 0.2% SDS for 1 min
11. ddH2O for 1 min
12. ddH2O for 1 min
13. dry slides at 800 rpm for 5 min
Store slides in the dark at RT (stable for >1 year).
1. Drying increases crosslinking efficiency. Several days or more is OK.
2. All washing steps are done in a hood in different glass staining dishes with filtered solutions.
3. Dissolve 1.0 g NaBH4 in 300 ml PBS. Add 100 ml 100% EtOH to reduce bubbling. Prepare JUST PRIOR to use!