Shirley Zhu/ total RNA labeling for Corning array

Fluorescent Probe Labeling for Microarray hybridization

-RT setup

total RNA 50-70 ug

Anchored oligo dT primer 4-5 ug

DEPC/H2O up to 15.4 ul

-Vortex and quick spin

-Incubate 70ºC for 10 min (Program: hyb 70C)

-Chill on ice for 1-2 min, quick spin and keep on ice

-RT Reaction for each individual tube: make a master mix of the first three reagents:

5X superscript II first strand buffer 6 ul

0.1 M DTT 3 ul

50 X dNTPs 0.6ul

(500 uM dATP/dCTP/dGTP, 200 uM dTTP)

Add these reagents to each tube individually:

Cy3 (pink, for Ref. RNA, always) or

Cy5 (blue, for samples, always) dUTP 3 ul

Superscript II (BRL) 2 ul

Total volume: 30ul

-Mix well by tabbing gently and spin down

-Incubate at 42ºC for 1 hour. Qui (Program: hyb1)

-Add another 1 ul of Superscript II for RT booster and mix gently and spin down

-Incubate at 42ºC for 1 hour (Program: hyb1)

-Then cool on ice and add 3 ul of 0.5M EDTA stop solution, mix gently and quick spin

-Pool Cy3 and Cy5 samples to a microcon ( Option: pool all Cy3 sample together first, then add 30 ul to each microcon)

-Wash1: Add 450ul of 1X TE (pH 7.4) mix well by inverting tubes,spin 11 min at 12K g at RT,

-Wash2: pour off flow through, add 500 ul 1X TE (pH7.4) to each centricon, spin 11 min at 12Kg at RT

-Wash3: pour off flow through, add 450 1X TE (pH7.4), 20 ul of Human Cot1 DNA, 2ul of 10ug/ul polyA RNA, and 2 ulof 5ug/ul tRNA, mix and spin for 12 min at 12K at RT. Concentrate to a volume of less than 32 ul.

-Invert centricon into a new tib(lid cut off) and spin for 2 min at 12K g at RT to recover the probe.

-Transfer probe to a microtube to adjust volume to 32 ul

-Add 6.8 ul 20XSSC, and mix well

-Then add 1.2 ul 10%SDS to probe ( wipe exess SDS off exterior of pipette tip using latex glove before adding to probe ). Mix by tapping lightly and quick spin to minimize bubbles.

-Denature probe by heating for 2 min at 100C then incubate at 37C for 20-25 min.

-Prewarm hybridization chambers at this time with arrays inside( at 37C in slide warmer)

-Spin sample for 5 min

-And keep sample at 37 C

-Place 39 ul of probe onto array under a 22mm X 40 mm glass cover slip; Add about 2ul of 3XSSC in 8-10 drops onto the middle axis of the array coverslip away from the actual array border for hydration purposes.

-Assemble the Hyb chamber with the array slide in it, turn the screws gently till you can’t move them anymore and place into a 65ºC water bath overnight

Next day:

-Pullout the Hyb chamber and dry off the excess H2O

-Disassemble the Hyb chamber, and quickly place the slides tilted with the coverslip slightly down into a slide rack in a washing chamber that contains 2XSSC/0.03 % SDS (RT), repeat this, individually for each array, one at a time, until all are done; and wait until the coverslip falls off.

-Then transfer the slides to 2X SSC/0.03%SDS at 65C, shake the slide holder up and down vigorously for 5 min, making sure slides never out solution.

-Wash slides in 2XSSC for 5 min, same as above or with a shaker

-Wash slides in 1XSSC for 5 min, same as above

-Wash slides in 0.2XSSC for 5 min, twice

-Spin slides down in centrifuge at 500 rpm for 5 min (prepare everything in advance, so transfer of slide rack to holder is very quickly done)

- Clean box needed to transport slides to scanner

-Scan immediately!

Washing buffer:

20X SSC stock solution 10% SDS

500 ml of 2X SSC/0.03% SDS 50 ml 1.5 ml

500 ml of 2X SSC 50 ml

500 ml of 1X SSC 25 ml

500 ml of 0.2 X SSC 5 ml

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