Tag Archives: RNA quantification

RNA Isolation – C.gigas Larvae from 20110412 & 20110705

RNA was isolated from C.gigas larvae collected from Taylor Shellfish hatchery on the dates noted above. Samples were in RNA Later. RNA Later was removed. Attempted homogenization with a pestle proved futile, as a significant quantity of larvae were sticking to the pestle and were nearly impossible to wash off using TriReagent as a rinsing agent. Due to this, all samples were vortexed for 1min in 1mL of TriReagent. It should be noted that the TriReagent took on a cloudy appearance and even showed some separation into two layers upon letting the samples sit. This was not normal and I was immediately concerned about the high salt content from residual RNA Later. Samples were treated normally with the following changes:

  • Aqueous phase after chloroform treatment was clear, but grey in color. This is not necessarily unusual.

  • Addition of isopropanol triggered immediate precipitation of a dark grey material.

  • “Pelleting” of the RNA after the isopropanol precipitation resulted in a gooey grey material that did NOT pellet, and a clear supernatant. The grey goo was transferred to a clean tube. An additional 500uL of isopropanol was added to the clear supernatant of two samples (#140 & #142), as well as to the grey goo. The addition of isopropanol to the clear supe resulted in an immediate precipitation of white salt-like material. The isopropanol appeared to have no effect on the grey goo. All samples were stored @-20C in their existing conditions until 20120116.

  • Since the two samples that were treated with an additional 500uL of isopropanol produced an excess of salt precipitation, I instead added 1mL of 70% EtOH to all the remaining samples; both the clear supernatants and the grey goo. The idea being that the higher water content in the 70% EtOH would help to keep the salts in solution, while precipitating the RNA. Samples were pelleted. All of the grey goo samples produced a white pellet. The grey goo seemed unchanged. Supernatants (including grey goos) were discarded and the resulting pellets from all samples were washed in this fashion were washed three more times.

  • Pellets were resuspended in 25uL of 0.1% DEPC-H2O and stored @ -80C until 20120123.

  • Samples were spec’d on the Roberts’ Lab NanoDrop 1000.

Results:

Spreadsheet of OD readings is here.

Since samples were split into two (clear supernatant and grey goo), they were kept separate through the remainder of the process. Sample names are appended with “-1″ or “-2″. “-1″ samples are grey goo samples and the “-2″ samples are the clear supernatant samples.

Overall, most of the grey goo samples appear to have produced the highest yields and highest quality of RNA, although this is not true for all of the samples.

DNase – Hard Clam Gill RNA (from earlier today)

DNased 5ug of RNA from each sample with Ambion’s Turbo DNA-free Kit, according to the manufacturer’s rigorous protocol. Samples were spec’d and stored @ -80C in the “Hard Clam V.t. Experiment RNA” box.

Results:

Due to lack of a positive control (and lack of primers known to amplify gDNA), these DNased RNA samples will NOT be checked to verify elimination of gDNA carryover at this time. Will proceed with making cDNA for qPCR anyway.

RNA Isolation – Hard Clam Gill Tissue from Vibrio Experiment (see Dave’s Notebook 5/2/2011)

Isolated RNA in 1mL of Tri-Reagent according to the manufacturer’s protocol. Also, finished RNA isolation of samples that were started 20110506. Samples were resuspended in 50uL 0.1%DEPC-H2O and spec’d.

Results:

mRNA Isolation – Pooled Black Abalone Dg RNA (from Abalone Dg Exp 1)

mRNA was isolated for SOLiD sequencing by HTGU. Made two pools of San Nick RNA (Control and Exposed) using equal amounts (5ug) of each individual sample. Individual samples used can be found here. mRNA was isolated using Ambion’s Micro PolyAPurist Kit according to protocol. Procedure was performed two times on each pool and then EtOH precipitated. Samples were resuspended in 10uL of The RNA Storage Solution provided in the kit and spec’d on the Roberts Lab ND1000. Samples were stored @ -80C in the “Next Gen Sequencing Libraries” box.

Results:

Yields are pretty good from both samples (~500ng). However, the OD260/280 values are rather poor.

DNase – C.gigas BB01 (PROPS) RNA (from 20090507)

Since the previous DNase treatment failed for this sample, will repeat but will start with less RNA (5ug instead of 10ug). Need more DNased RNA to finish repeating of PROPS. Some samples had insufficient quantities of DNased RNA remaining in BB01. Used 5ug of RNA and followed Ambion’s “rigorous” protocol, utilizing a total of 2uL of DNAse for each sample. Briefly, samples were incubated @ 37C for 30mins, an additional 1uL of DNase was added to each sample, mixed and incubated for an additional 30mins @ 37C. After finishing protocol, samples were spec’d.

DNase Rxn Calcs:

BB01 (1.824ug/uL): 5ug/1.824ug/uL = 2.74uL RNA + 42.26uL H2O (to 45uL) + 5uL 10X DNase Buffer = 50uL

Results:

RNA looks OK, based on OD260/280. Would like that value to be higher, though. OD260/230 is low, which is typical post-DNased treatment. Will check for residual gDNA via qPCR.

DNase – C.gigas BB01 from 20110225

Used EtOH precipitated BB01 RNA from 20110225 and followed Ambion’s “rigorous” protocol, utilizing a total of 2uL of DNAse. Briefly, samples were incubated @ 37C for 30mins, an additional 1uL of DNase was added to each sample, mixed and incubated for an additional 30mins @ 37C. After finishing protocol, samples were spec’d.

Results:

RNA looks good, based on the OD260/280. As usual after DNasing, the OD260/230 is on the low side. Will check for residual gDNA via qPCR.

DNase – C.gigas BB01 from 20110216

Used EtOH precipitated BB01 RNA from 20110216 and followed Ambion’s “rigorous” protocol, utilizing a total of 2uL of DNAse. Briefly, samples were incubated @ 37C for 30mins, an additional 1uL of DNase was added to each sample, mixed and incubated for an additional 30mins @ 37C. After finishing protocol, samples were spec’d.

Results:

First reading had an air bubble and should be ignored. DNased RNA looks good, based on 260/280 ratios. As is usually the case for DNased RNA, the 260/230 ratios are on the low side. Will check DNased RNA for residual gDNA.

DNase – C.gigas BB/DH (PROPS) RNA (from 20090507)

Need more DNased RNA to finish repeating of PROPS. Some samples had insufficient quantities of DNased RNA remaining in BB01 and BB09. Used 10ug of each RNA and followed Ambion’s “rigorous” protocol, utilizing a total of 2uL of DNAse for each sample. Briefly, samples were incubated @ 37C for 30mins, an additional 1uL of DNase was added to each sample, mixed and incubated for an additional 30mins @ 37C. After finishing protocol, samples were spec’d.

DNase Rxn Calcs:

BB01 (1.824ug/uL): 10ug/1.824ug/uL = 5.48uL RNA + 39.52uL H2O (to 45uL) + 5uL 10X DNase Buffer = 50uL

BB09 (0.506ug/uL): 10ug/0.506ug/uL = 19.77uL RNA + 25.23uL H2O (to 45uL) + 5uL 10X DNase Buffer = 50uL

Results:

260/280 values look great. 260/230 values look bad, but this is not unusual for samples post-DNase treatment.

RNA Isolation – Various C.gigas Tissue from 20110111

RNA was isolated in 1mL TriReagent, according to protocol. Samples were resuspended in 50uL 0.1% DEPC-H2O and spec’d. RNA was stored @ -80C in “Shellfish RNA Box #4

Results:

RNA looks OK. Not surprising, but mantle and Dg/Gonad tissues ended up with poor OD260/230 ratios. This has been observed in the past with these tissue types.

RNA Isolation – Various C.gigas Tissue from 20110111

RNA was isolated in 1mL TriReagent, according to protocol. Samples were resuspended in 50uL 0.1% DEPC-H2O and spec’d. RNA was stored @ -80C in “Shellfish RNA Box #4“.

Results:

Overall, all RNA looks very good (based on 260/280 and 260/230 values).