Authors would like to acknowledge Malcom Campbell and Todd Eckdahl with the Genome Consortium for Active Teaching (GCAT) and the HHMI-Science Education Alliance - Phage Hunters Advancing Genomics and Evolutionary Science (SEA-PHAGES) program.
This project was supported by grants from the National Center for Research Resources (P20RR016460) and the National Institute of General Medical Sciences (P20GM103429) from the National Institutes of Health. This research was supported in part by the National Science Foundation under grant# IIA-1457888. Additionally institutional (Ouachita Baptist University) funds were provided through the J.D. Patterson Summer Research Fellowship.

1. Designing and Ordering Oligonucleotides with the Appropriate Sticky Ends
<ol>
	<li>Identify potential rho-independent terminators through genomic analysis using programs that are freely available online.7</li>
	<li>When working with double stranded DNA, determine the orientation of the terminator to be tested.7 The pGR-Blue plasmid only verifies terminators ligated in the 5&#39; to 3&#39; direction on the top (forward strand).
	<ol>
		<li>Convert a bottom (reverse) strand terminator to its reversed complement to reorient the sequence for testing in pGR-Blue using free online software, e.g., ApE.</li>
	</ol>
	</li>
	<li>After the orientation is determined to be correct, add the sticky end &#34; 5&#39;-CGAC-3&#39; &#34; to the 5&#39; end of the top strand. Add the sticky end &#34; 5&#39;-CCGC-3&#39; &#34; to the 5&#39; end of the bottom strand. 8 This will ensure that ligated insert will be inserted in the appropriate orientation using GGA.</li>
	<li>Once sequences are determined, order as single stranded oligonucleotides commercially.</li>
</ol>
2. Annealing Oligonucleotides (Applies Only to Freeze-dried DNA)
<ol>
	<li>Re-suspend individual oligonucleotides in nuclease free water to a concentration of 100 &#181;M.</li>
	<li>Make 10x annealing buffer: 1 M NaCl and 100 mM Tris-HCl pH 7.4. Annealing buffer can be stored at 4 &#176;C for several weeks. Once annealing buffer is made and oligonucleotides are re-suspended, begin the annealing8.</li>
	<li>For each terminator to be tested, add 16 &#181;l of ultra-pure water to a 1.5 ml microcentrifuge tube.</li>
	<li>Add 2 &#181;l of 10x annealing buffer to each microcentrifuge tube.</li>
	<li>Add 1 &#181;l of the top strand oligonucleotide (100 &#181;M) from the desired terminator.</li>
	<li>Add 1 &#181;l of the bottom strand oligonucleotide (100 &#181;M) from the desired terminator.</li>
	<li>Create a boiling water bath using a 1,000 ml beaker containing approximately 400 ml of tap water and place on a hot plate.</li>
	<li>Place the microcentrifuge tubes from step 2.6 in a float and boil for 4 min. After 4 min, turn off the heat plate but leave the tube and float in the water bath to slowly cool O/N (18 hr) 8. Store the annealed terminators at -20 &#176;C.</li>
</ol>
3. Golden Gate Assembly (Standard Mix &#8212; Cost Efficient)
<ol>
	<li>Make a 40 nM dilution of the annealed terminators. Add 124 &#181;l of nuclease free water to 1 &#181;l of annealed terminators mix (100 &#181;M).
	<ol>
		<li>Centrifuge samples for 30 sec at 10,000 x g and store on ice.</li>
	</ol>
	</li>
	<li>Into a new tube appropriate for the thermocycler being used, add 6 &#181;l of nuclease free water.</li>
	<li>Add 1 &#181;l of commercial DNA Ligase Buffer [300 mM Tris-HCl (pH 7.7-7.8), 100 mM MgCl2, 100 mM DTT, and 10 mM ATP]. Perform all subsequent steps on ice.</li>
	<li>Add 1 &#181;l of pGR-Blue (35-50 ng/&#181;l) destination plasmid to the microcentrifuge tube.</li>
	<li>Add 1 &#181;l of the 40 nM annealed terminators to the microcentrifuge tube.</li>
	<li>Add 0.5 &#181;l commercial high-fidelity BsaI restriction endonuclease to the microcentrifuge tube.</li>
	<li>Add 0.5 &#181;l of commercial DNA ligase to the microcentrifuge tube.</li>
	<li>Centrifuge the reaction mixture at 10,000 x g for 120 sec. Then place the tube directly into the thermocycler.</li>
	<li>Run the thermocycler program: 20 cycles of 1 min at 37 &#176;C followed by 1 min at 16 &#176;C, followed by 1 cycle of 15 min at 37 &#176;C. Use samples immediately or freeze and store at -20 &#176;C.8</li>
</ol>
4. Golden Gate Assembly (Commercial Master Mix&#160;&#8212; Time Efficient)
<ol>
	<li>Add 124 &#181;l of nuclease free water to 1 &#181;l of the 100 &#181;M annealed terminators created in step 2. This dilutes the terminator DNA concentration to 40 nM. Perform this step in a new, labeled 1.5 ml microcentrifuge tube.</li>
	<li>Into a new tube appropriate for the thermocycler, add 14 &#181;l of nuclease free water. Make sure the new tube is labeled accordingly.</li>
	<li>Add 2 &#181;l of Commercial Master Mix Buffer to the microcentrifuge tube.</li>
	<li>Add 1 &#181;l of pGR-Blue plasmid (35-50 ng/&#181;l) to the microcentrifuge tube.</li>
	<li>Add 2 &#181;l of the 40 nM annealed terminators to the microcentrifuge tube.</li>
	<li>Add 1 &#181;l of Commercial Master Mix to the microcentrifuge tube.</li>
	<li>Centrifuge the 40 nM tube at 10,000 x g for 120 sec. Then place the tube directly into the thermocycler.</li>
	<li>Run the thermocycler program: 1 cycle of 60 min at 37 &#176;C followed by 1 cycle of 15 min at 55 &#176;C. Use samples immediately or freeze and store at -20 &#176;C.</li>
</ol>
5. Transformation and Colony Selection
<ol>
	<li>Prepare Luria Base (LB) agar Petri plates containing 1 mM concentration of ampicillin (Amp) and a 10 mM concentration of arabinose (arb). Prepare at least 10 ml of 1 M L-arabinose stock solution because this stock solution will be used in later steps.</li>
	<li>Use any high-efficient (108 - 109 transformants/&#181;g ) chemically competent E. coli (JM109) cells for transformation.9 For best results, add 3-5 &#181;l of the ligation reaction to 50 &#181;l of competent cells. When using chemical competent cells, follow the transformation protocol specific to the cells being used.</li>
	<li>Spread half (25 &#181;l) of the transformed cells onto pre-warmed LB (Amp/arb) agar plates using a sterile L-shaped &#34;hockey stick&#34; and incubate O/N at 37 &#176;C. Due to ampicillin&#39;s rapid rate of decomposition, do not incubate at 37 &#176;C over 24 hr.</li>
	<li>Perform colony selection based on color by visual inspection. A successful ligation should be white/yellow in visible light and fluoresce green under blue (450 nm) or UV light. An unsuccessful ligation will produce a colony that is blue in color under visible light after 18 - 20 hr.</li>
</ol>
6. Verification and Quantification of Terminator
<ol>
	<li>Prepare 5 ml sterile LB-broth tubes with 1 mM ampicillin and 10 mM arabinose. The number of tubes needed is dependent on the number of terminators being tested plus controls (cells with ampicillin resistance that do not fluoresce and cells containing the uncut pGR-Blue plasmid).</li>
	<li>Under visible light pick 2-3 white/yellow colonies (step 5.4) using a sterile loop. Allow the samples to incubate in broths on a shaker at 37 &#176;C and 160 rpm for 16-18 hr. Do not incubate these samples for more than 24 hr.
	<ol>
		<li>Optionally, use a spectrophotometer to determine optical cell density at 600 nm (OD600) to ensure adequate cell growth. Generally, an OD600 of ~0.8-1.0 is observed after 16-18 hr of growth.</li>
	</ol>
	</li>
	<li>Use a sterile 96-well plate for the remaining steps. Conduct these steps in an aseptic environment and in triplicate. Add 199 &#181;l of sterile LB+ Amp/arabinose broth (1 mM ampicillin/10 mM arabinose) to each well. Include room on the plate for three separate controls.
	<ol>
		<li>Use the following three controls: A well (1) containing LB + Amp/arabinose broth only and a well (2) for untransformed competent cells (blank) to serve as a blank. For quantification (3) of the terminator strength, cells containing uncut original pGR or containing pGR-Blue ligated with a non-terminating sequence should be included (reference control for quantification). See Figure 1 for plate reader layout.</li>
	</ol>
	</li>
	<li>Pipet 1 &#181;l of the cell solution from the O/N broths into individual wells of the 96-well plate.</li>
	<li>Seal plates with a breathable cover and shake for 18-20 hr at 37 &#176;C and 160 rpm.</li>
	<li>Using a plate reader, determine OD600 by reading absorbance at 600 nm. Measure GFP fluorescence as follows: excitation 395 and emission 509. Measure RFP fluorescence as follows: excitation 575 and emission 605. After 18-20 hr, the OD600 should be approximately 0.5.</li>
	<li>To normalize for variation in growth, use the equation: <img alt="Equation 1" src="/files/ftp_upload/54064/54064eq1.jpg" /> for both GFP and RFP.</li>
	<li>After normalization, determine relative terminator strength using the equation&#160; <img alt="Equation 2" src="/files/ftp_upload/54064/54064eq2.jpg" /></li>
</ol>

<ol>
	<li>Li, J., Zhang, Y. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Relationship+between+promoter+sequence+and+its+strength+in+gene+expression.">Relationship between promoter sequence and its strength in gene expression.</a> Eur Phys J E Soft Matter. 37 (9), (2014).</li><li>Engler, C., Kandzia, R., Marillonnet, S. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=A+one+pot,+one+step,+precision+cloning+method+with+high+throughput+capability.">A one pot, one step, precision cloning method with high throughput capability.</a> PLoS One. 3 (11), e3647 (2008).</li><li>Lampropoulos, A., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=GreenGate---a+novel,+versatile,+and+efficient+cloning+system+for+plant+transgenesis.">GreenGate---a novel, versatile, and efficient cloning system for plant transgenesis.</a> PLoS One. 8 (12), e83043 (2013).</li><li>Chen, Y. J., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Characterization+of+582+natural+and+synthetic+terminators+and+quantification+of+their+design+constraints.">Characterization of 582 natural and synthetic terminators and quantification of their design constraints.</a> Nat Methods. 10 (7), 659-664 (2013).</li><li>Woodin, T., Carter, V. C., Fletcher, L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+and+change+in+biology+undergraduate+education,+a+call+for+action--initial+responses.">Vision and change in biology undergraduate education, a call for action--initial responses.</a> CBE Life Sci Educ. 9 (2), 71-73 (2010).</li><li>Vasaly, H. L., Feser, J., Lettrich, M. D., Correa, K., Denniston, K. J. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vision+and+change+in+the+biology+community:+snapshots+of+change.">Vision and change in the biology community: snapshots of change.</a> CBE Life Sci Educ. 13 (1), 16-20 (2014).</li><li>Naville, M., Ghuillot-Gaudeffroy, A., Marchais, A., Gautheret, D. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=ARNold:+a+web+tool+for+the+prediction+of+Rho-independent+transcription+terminators.">ARNold: a web tool for the prediction of Rho-independent transcription terminators.</a> RNA Biol. 8 (1), 11-13 (2011).</li><li>Campbell, A. M., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=pClone:+Synthetic+Biology+Tool+Makes+Promoter+Research+Accessible+to+Beginning+Biology+Students.">pClone: Synthetic Biology Tool Makes Promoter Research Accessible to Beginning Biology Students.</a> CBE Life Sci Educ. 13 (2), 285-296 (2014).</li><li>Rhee, J. I., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Influence+of+the+medium+composition+and+plasmid+combination+on+the+growth+of+recombinant+Escherichia+coli+JM109+and+on+the+production+of+the+fusion+protein+EcoRI::SPA.">Influence of the medium composition and plasmid combination on the growth of recombinant Escherichia coli JM109 and on the production of the fusion protein EcoRI::SPA.</a> J Biotechnol. 55 (2), 69-83 (1997).</li><li>Dirla, S., Chien, J. Y., Schleif, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Constitutive+mutations+in+the+Escherichia+coli+AraC+protein.">Constitutive mutations in the Escherichia coli AraC protein.</a> J Bacteriol. 191 (8), 2668-2674 (2009).</li><li>Schleif, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Regulation+of+the+L-arabinose+operon+of+Escherichia+coli.">Regulation of the L-arabinose operon of Escherichia coli.</a> Trends Genet. 16 (12), 559-565 (2000).</li><li>Kosuri, S., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Composability+of+regulatory+sequences+controlling+transcription+and+translation+in+Escherichia+coli.">Composability of regulatory sequences controlling transcription and translation in Escherichia coli.</a> Proc Natl Acad Sci U S A. 110 (34), 14024-14029 (2013).</li><li>Sharon, E., et al. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Inferring+gene+regulatory+logic+from+high-throughput+measurements+of+thousands+of+systematically+designed+promoters.">Inferring gene regulatory logic from high-throughput measurements of thousands of systematically designed promoters.</a> Nat Biotechnol. 30 (6), 521-530 (2012).</li></ol>

The authors have nothing to disclose.

The most important step in this protocol is proper oligonucleotide design prior to ordering. The oligonucleotides must have the appropriate sticky ends added to the 5&#39; ends of both the top and bottom strands to ensure that GGA incorporation is possible. Additionally, it is important to switch the orientation of left facing terminators (terminators that stop transcription on the bottom strand) to that of right facing (terminates transcription on the top strand) terminators because GFP and RFP expression is in the righ...

Large synthetic biology projects necessitate the use of highly effective transcription terminators to help regulate gene expression. Identification of novel terminators requires bioinformatic analysis of novel genomes. However, as increasing amounts of bioinformatic software are developed, each with a unique algorithm utilized for prediction, more discrepancy between putative results occurs. Because this process is somewhat subjective and is done in silico, these predictions need biological confirmation.1 Additionally, the volume of putative terminators identified through in-silico analysis requires the use of cloning strategies that can be completed in a relatively short time frame. 
The PGR-Blue plasmid is a modification of the PGR plasmid that has been redesigned to use Golden Gate Assembly (GGA) to simplify the cloning procedure by allowing for all reaction steps to be simultaneously performed in one micro-centrifuge tube.2,3 Color selection was incorporated into the plasmid to increase the ease of identifying positive colonies. A successful ligation should be white/yellow in visible light and fluoresce green under blue (450 nm) or ultraviolet (UV) light when grown on plates containing arabinose. Because uncut pGR-blue contains a blue chromo protein (amilCP), colonies containing an unmodified plasmid are blue under visible light. This simplification along with the streamlined protocol allows researchers to proceed from bioinformatic identification to biological confirmation in three to four days. The design nature of this system can be beneficial both in the research lab and in educational settings.
The pGR-Blue plasmid allows for quantification of terminator strength.4 A single arabinose inducible promoter is used to produce green fluorescent protein (GFP) and red fluorescent protein (RFP). The terminator is cloned into the plasmid after the GFP sequence but before the RFP sequence, thus stopping the transcription of the RFP protein. The strength of the terminator is determined by the ratio of GFP produced to RFP produced. 
The Vision and Change5 report suggested that Science, Technology, Engineering and Math (STEM) education incorporate research based experiences into the classroom.6 However, this requires the development of protocols that can be done by students with limited skill sets in a defined time frame. While the protocol can be accomplished in as little as three days, it was also designed so that each major step could be accomplished in a separate weekly (2-3 hr) lab period to create a Course Research Experience (CRE). When used in this manner, the procedure will take between three and six weeks and is appropriate for both introductory and advanced courses in Genetics, Cell Biology or Bioinformatics.

<table border="0" cellpadding="0" cellspacing="0" width="887">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:295px;">pGR-Blue Plasmid</td>
			<td style="width:243px;">Addgene</td>
			<td style="width:115px;">68374</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">pGR-Plasmid</td>
			<td>Addgene</td>
			<td style="width:115px;">46002</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">AeraSeal-(Sterile Sheets)</td>
			<td>Excel Scientific</td>
			<td>BS-25</td>
			<td style="width:235px;">Sterile Sheets only</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">10X T4 DNA ligase Buffer</td>
			<td>NEB</td>
			<td></td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">BsaI-HF</td>
			<td>NEB</td>
			<td>R3535S</td>
			<td style="width:235px;">The non-HF enzyme will work but is less heat stable.&#160;</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">NEB Golden Gate Assembly Mix</td>
			<td>NEB</td>
			<td>E1600S</td>
			<td style="width:235px;">Commerial Master Mix refered to in the protocol.</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">T4 DNA ligase</td>
			<td>NEB</td>
			<td>M0202S</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Round Microcentrifuge Floating Rack</td>
			<td>Nova Tech International</td>
			<td>F18875-6401</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="20">
			<td height="20" style="height:21px;">Ampicillin sodium salt</td>
			<td>Sigma Aldrich</td>
			<td>A9518</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">L-(+)-Arabinose</td>
			<td>Sigma Aldrich</td>
			<td>A-3256</td>
			<td style="width:235px;">D-Arabinose will not induce the pBAD promoter</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Luria Base (LB) - Broth, Miller</td>
			<td>Sigma Aldrich</td>
			<td>L1900</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Luria Base (LB) - Agar , Miller&#160;</td>
			<td>Sigma Aldrich</td>
			<td>L2025</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tecan-Infinite M200 Plate Reader</td>
			<td>Tecan</td>
			<td></td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">Mix &#38; Go Competent Cells - Strain JM109</td>
			<td>Zymo Research</td>
			<td>T3005</td>
			<td style="width:235px;">Use company recommended transformation protocol</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;">ApE: A plasmid editor-software</td>
			<td style="width:243px;">http://biologylabs.utah.edu/jorgensen/wayned/ape/</td>
			<td></td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Tris-HCl, Molecular Grade</td>
			<td>Promega</td>
			<td>H5121</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:295px;">Sodium Chloride (Crystalline/Biological, Certified)</td>
			<td>Fisher Chemical</td>
			<td>S671</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Comercial Oligonucleotide synthesis</td>
			<td>Integrated DNA Technologies (IDT)</td>
			<td></td>
			<td style="width:235px;">http://www.idtdna.com/site</td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:295px;">Microtest Tissue Culture Plates- 96 well (Sterile)</td>
			<td>Falcon</td>
			<td>35-3072</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">mycobacteriophage &#34;Bernal13&#34;</td>
			<td>Genebank</td>
			<td>KJ510413</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nuclease Free Water</td>
			<td>Integrated DNA Technologies (IDT)</td>
			<td>IDT004</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Sterile, L-shaped Hockey-Stick Cell</td>
			<td>Life Science Products</td>
			<td>6444-S1</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">Nano-Drop 2000c UV-Vis Spectrometer</td>
			<td>Thermo Scientific</td>
			<td>2000c</td>
			<td style="width:235px;"></td>
		</tr>
		<tr height="42">
			<td height="42" style="height:42px;width:295px;">ARNold: a web tool for the prediction of Rho-independent transcription terminators.</td>
			<td style="width:243px;">http://rna.igmors.u-psud.fr/</td>
			<td></td>
			<td style="width:235px;"></td>
		</tr>
	</tbody>
</table>

rapid verification of terminators using the pgr-blue plasmid and golden gate assembly

The goal of this protocol is to allow for the rapid verification of bioinformatically identified terminators. Further, the plasmid (pGR-Blue) is designed specifically for this protocol and allows for the quantification of terminator efficiency. As a proof of concept, six terminators were bioinformatically identified in the mycobacteriophage Bernal13. Once identified, terminators were then made as oligonucleotides with the appropriate sticky ends and annealed together. Using Golden Gate Assembly (GGA), terminators were then cloned into pGR-Blue. Under visible light, false positive colonies appear blue and positively transformed colonies are white/yellow. After induction of an arabinose inducible promoter (pBad) with arabinose, colony strength can be determined by measuring the ratio of green fluorescent protein (GFP) produced to red fluorescent protein (RFP) produced. With pGR-Blue, the protocol can be completed in as little as three days and is ideal in an educational setting. Additionally, results show that this protocol is useful as a means for understanding in silico predictions of terminator efficiency related to the regulation of transcription.

This protocol will produce cells containing pGR-Blue with a terminator ligated between GFP and RFP using Golden Gate Assembly (Figure 2). Positive colonies containing ligated insert can be selected based on color. In visible light positive colonies will be white/yellow and false positives will produce blue colonies after 18-20 hr of incubation at 37 &#176;C (Figure 3).
After colony selection, a ...

Watch this Scientific Journal Video about Rapid Verification of Terminators Using the pGR-Blue Plasmid and Golden Gate Assembly at JoVE.com

Rapid Verification of Terminators Using the pGR-Blue Plasmid and Golden Gate Assembly

This protocol utilizes Golden Gate Assembly and the plasmid pGR-blue to rapidly quantify the strength of terminators found in silico.

The goal of this protocol is to allow for the rapid verification of bioinformatically identified terminators. Further, the plasmid (pGR-Blue) is designed ...

rapid-verification-terminators-using-pgr-blue-plasmid-golden-gate

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7.6K Views.  Ouachita Baptist University. This protocol utilizes Golden Gate Assembly and the plasmid pGR-blue to rapidly quantify the strength of terminators found in silico.

Video: Rapid Verification of Terminators Using the pGR-Blue Plasmid and Golden Gate Assembly

Purifying Plasmid DNA from Bacterial Colonies Using the Qiagen Miniprep Kit

Plasmid DNA purification from E. coli is a core technique for molecular cloning. Small scale purification (miniprep) from less than 5 ml of bacterial culture is a quick way for clone verification or DNA isolation, followed by further enzymatic reactions (polymerase chain reaction and restriction enzyme digestion). Here, we video-recorded the general procedures of miniprep through the QIAGEN's QIAprep 8 Miniprep Kit, aiming to introducing this highly efficient technique to the general beginners for molecular biology techniques. The whole procedure is based on alkaline lysis of E. coli cells followed by adsorption of DNA onto silica in the presence of high salt. It consists of three steps: 1) preparation and clearing of a bacterial lysate, 2) adsorption of DNA onto the QIAprep membrane, 3) washing and elution of plasmid DNA. All steps are performed without the use of phenol, chloroform, CsCl, ethidium bromide, and without alcohol precipitation. It usually takes less than 2 hours to finish the entire procedure.

Plasmid DNA purification from E. coli is a core technique for molecular cloning. Small scale purification (miniprep) from less than 5 ml of bacterial ...

Transformation of Plasmid DNA into E. coli Using the Heat Shock Method

Transformation of plasmid DNA into E. coli using the heat shock method is a basic technique of molecular biology. It consists of inserting a foreign plasmid or ligation product into bacteria. This video protocol describes the traditional method of transformation using commercially available chemically competent bacteria from Genlantis. After a short incubation in ice, a mixture of chemically competent bacteria and DNA is placed at 42&deg;C for 45 seconds (heat shock) and then placed back in ice. SOC media is added and the transformed cells are incubated at 37&deg;C for 30 min with agitation. To be assured of isolating colonies irrespective of transformation efficiency, two quantities of transformed bacteria are plated. This traditional protocol can be used successfully to transform most commercially available competent bacteria. The turbocells from Genlantis can also be used in a novel 3-minute transformation protocol, described in the instruction manual.

Transformation of plasmid DNA into E. coli using the heat shock method is a basic technique of molecular biology. It consists of inserting a foreign ...

In Vitro Nuclear Assembly Using Fractionated Xenopus Egg Extracts

Nuclear membrane assembly is an essential step in the cell division cycle; this process can be replicated in the test tube by combining Xenopus sperm chromatin, cytosol, and light membrane fractions. Complete nuclei are formed, including nuclear membranes with pore complexes, and these reconstituted nuclei are capable of normal nuclear processes.

Nuclear membrane assembly is an essential step in the cell division cycle; this process can be replicated in the test tube by combining Xenopus sperm chromatin, cytosol, and light membrane fractions. Complete nuclei are formed, including nuclear membranes with pore complexes, and these reconstituted nuclei are capable of normal nuclear processes.

Nuclear membrane assembly is an essential step in the cell division cycle; this process can be replicated in the test tube by combining Xenopus sperm ...

Assembly, Loading, and Alignment of an Analytical Ultracentrifuge Sample Cell

The analytical ultracentrifuge (AUC) is a powerful biophysical tool that allows us to record macromolecular sedimentation profiles during high speed centrifugation. When properly planned and executed, an AUC sedimentation velocity or sedimentation equilibrium experiment can reveal a great deal about a protein in regards to size and shape, sample purity, sedimentation coefficient, oligomerization states and protein-protein interactions.
This technique, however, requires a rigorous level of technical attention. Sample cells hold a sectored center piece sandwiched between two window assemblies. They are sealed with a torque pressure of around 120-140 in/lbs. Reference buffer and sample are loaded into the centerpiece sectors and then after sealing, the cells are precisely aligned into a titanium rotor so that the optical detection systems scan both sample and reference buffer in the same radial path midline through each centerpiece sector while rotating at speeds of up to 60, 000 rpm and under very high vacuum
Not only is proper sample cell assembly critical, sample cell components are very expensive and must be properly cared for to ensure they are in optimum working condition in order to avoid leaks and breakage during experiments. Handle windows carefully, for even the slightest crack or scratch can lead to breakage in the centrifuge. The contact between centerpiece and windows must be as tight as possible; i.e. no Newton s rings should be visible after torque pressure is applied. Dust, lint, scratches and oils on either the windows or the centerpiece all compromise this contact and can very easily lead to leaking of solutions from one sector to another or leaking out of the centerpiece all together. Not only are precious samples lost, leaking of solutions during an experiment will cause an imbalance of pressure in the cell that often leads to broken windows and centerpieces. In addition, plug gaskets and housing plugs must be securely in place to avoid solutions being pulled out of the centerpiece sector through the loading holes by the high vacuum in the centrifuge chamber. Window liners and gaskets must be free of breaks and cracks that could cause movement resulting in broken windows.
This video will demonstrate our procedures of sample cell assembly, torque, loading and rotor alignment to help minimize component damage, solution leaking and breakage during the perfect AUC experiment.

The analytical ultracentrifuge (AUC) sample cell holds sample and reference buffer and during experiments and is exposed to high vacuum and rotor speeds up to 60,000 rpm. This video will demonstrate the rigorous attention to detail necessary for assembly, loading and alignment of this very important component of an AUC experiment.

The analytical ultracentrifuge (AUC) is a powerful biophysical tool that allows us to record macromolecular sedimentation profiles during high speed ...

Primary Culture and Plasmid Electroporation of the Murine Organ of Corti. 

In all mammals, the sensory epithelium for audition is located along the spiraling organ of Corti that resides within the conch shaped cochlea of the inner ear (fig 1). Hair cells in the developing cochlea, which are the mechanosensory cells of the auditory system, are aligned in one row of inner hair cells and three (in the base and mid-turns) to four (in the apical turn) rows of outer hair cells that span the length of the organ of Corti. Hair cells transduce sound-induced mechanical vibrations of the basilar membrane into neural impulses that the brain can interpret. Most cases of sensorineural hearing loss are caused by death or dysfunction of cochlear hair cells.
An increasingly essential tool in auditory research is the isolation and in vitro culture of the organ explant 1,2,9. Once isolated, the explants may be utilized in several ways to provide information regarding normative, anomalous, or therapeutic physiology. Gene expression, stereocilia motility, cell and molecular biology, as well as biological approaches for hair cell regeneration are examples of experimental applications of organ of Corti explants.
This protocol describes a method for the isolation and culture of the organ of Corti from neonatal mice. The accompanying video includes stepwise directions for the isolation of the temporal bone from mouse pups, and subsequent isolation of the cochlea, spiral ligament, and organ of Corti. Once isolated, the sensory epithelium can be plated and cultured in vitro in its entirety, or as a further dissected micro-isolate that lacks the spiral limbus and spiral ganglion neurons. Using this method, primary explants can be maintained for 7-10 days. As an example of the utility of this procedure, organ of Corti explants will be electroporated with an exogenous DsRed reporter gene. This method provides an improvement over other published methods because it provides reproducible, unambiguous, and stepwise directions for the isolation, microdissection, and primary culture of the organ of Corti.

Primary Culture and Plasmid Electroporation of the Murine Organ of Corti.

This procedure describes a method for the isolation and culture of the murine organ of Corti with or without the spiral limbus and spiral ganglion neurons. We also demonstrate a method for the expression of an exogenous reporter gene in the organ of Corti explant by electroporation.

In all mammals, the sensory epithelium for audition is located along the spiraling organ of Corti that resides within the conch shaped cochlea of the ...

Rapid PCR Thermocycling using Microscale Thermal Convection

Many molecular biology assays depend in some way on the polymerase chain reaction (PCR) to amplify an initially dilute target DNA sample to a detectable concentration level. But the design of conventional PCR thermocycling hardware, predominantly based on massive metal heating blocks whose temperature is regulated by thermoelectric heaters, severely limits the achievable reaction speed1. Considerable electrical power is also required to repeatedly heat and cool the reagent mixture, limiting the ability to deploy these instruments in a portable format.
Thermal convection has emerged as a promising alternative thermocycling approach that has the potential to overcome these limitations2-9. Convective flows are an everyday occurrence in a diverse array of settings ranging from the Earth's atmosphere, oceans, and interior, to decorative and colorful lava lamps. Fluid motion is initiated in the same way in each case: a buoyancy driven instability arises when a confined volume of fluid is subjected to a spatial temperature gradient. These same phenomena offer an attractive way to perform PCR thermocycling. By applying a static temperature gradient across an appropriately designed reactor geometry, a continuous circulatory flow can be established that will repeatedly transport PCR reagents through temperature zones associated with the denaturing, annealing, and extension stages of the reaction (Figure 1). Thermocycling can therefore be actuated in a pseudo-isothermal manner by simply holding two opposing surfaces at fixed temperatures, completely eliminating the need to repeatedly heat and cool the instrument.
One of the main challenges facing design of convective thermocyclers is the need to precisely control the spatial velocity and temperature distributions within the reactor to ensure that the reagents sequentially occupy the correct temperature zones for a sufficient period of time10,11. Here we describe results of our efforts to probe the full 3-D velocity and temperature distributions in microscale convective thermocyclers12. Unexpectedly, we have discovered a subset of complex flow trajectories that are highly favorable for PCR due to a synergistic combination of (1) continuous exchange among flow paths that provides an enhanced opportunity for reagents to sample the full range of optimal temperature profiles, and (2) increased time spent within the extension temperature zone the rate limiting step of PCR. Extremely rapid DNA amplification times (under 10 min) are achievable in reactors designed to generate these flows.

We describe a novel method to perform DNA replication via the polymerase chain reaction (PCR). Thermal convection is harnessed to continuously shuttle reagents between denaturing, annealing, and extension conditions by maintaining opposing surfaces of the reactor at constant temperature. This inherently simple design promises to make rapid PCR more accessible.

Many molecular biology assays depend in some way on the polymerase chain reaction (PCR) to amplify an initially dilute target DNA sample to a detectable ...

High-throughput Yeast Plasmid Overexpression Screen

The budding yeast, Saccharomyces cerevisiae, is a powerful model system for defining fundamental mechanisms of many important cellular processes, including those with direct relevance to human disease. Because of its short generation time and well-characterized genome, a major experimental advantage of the yeast model system is the ability to perform genetic screens to identify genes and pathways that are involved in a given process. Over the last thirty years such genetic screens have been used to elucidate the cell cycle, secretory pathway, and many more highly conserved aspects of eukaryotic cell biology 1-5. In the last few years, several genomewide libraries of yeast strains and plasmids have been generated 6-10. These collections now allow for the systematic interrogation of gene function using gain- and loss-of-function approaches 11-16. Here we provide a detailed protocol for the use of a high-throughput yeast transformation protocol with a liquid handling robot to perform a plasmid overexpression screen, using an arrayed library of 5,500 yeast plasmids. We have been using these screens to identify genetic modifiers of toxicity associated with the accumulation of aggregation-prone human neurodegenerative disease proteins. The methods presented here are readily adaptable to the study of other cellular phenotypes of interest.

Here we describe a plasmid overexpression screen in Saccharomyces cerevisiae, using an arrayed plasmid library and a high-throughput yeast transformation protocol with a liquid handling robot.

The budding yeast, Saccharomyces cerevisiae, is a powerful model system for defining fundamental mechanisms of many important cellular processes, ...

Rapid Synthesis and Screening of Chemically Activated Transcription Factors with GFP-based Reporters

Synthetic biology aims to rationally design and build synthetic circuits with desired quantitative properties, as well as provide tools to interrogate the structure of native control circuits. In both cases, the ability to program gene expression in a rapid and tunable fashion, with no off-target effects, can be useful. We have constructed yeast strains containing the ACT1 promoter upstream of a URA3 cassette followed by the ligand-binding domain of the human estrogen receptor and VP16. By transforming this strain with a linear PCR product containing a DNA binding domain and selecting against the presence of URA3, a constitutively expressed artificial transcription factor (ATF) can be generated by homologous recombination. ATFs engineered in this fashion can activate a unique target gene in the presence of inducer, thereby eliminating both the off-target activation and nonphysiological growth conditions found with commonly used conditional gene expression systems. A simple method for the rapid construction of GFP reporter plasmids that respond specifically to a native or artificial transcription factor of interest is also provided.

This protocol describes an experimental procedure for the rapid construction of artificial transcription factors (ATFs) with cognate GFP reporters&#160;and quantification of the ATFs ability to stimulate GFP expression via flow cytometry.

Synthetic biology aims to rationally design and build synthetic circuits with desired quantitative properties, as well as provide tools to interrogate the ...

Generation of Plasmid Vectors Expressing FLAG-tagged Proteins Under the Regulation of Human Elongation Factor-1&#945; Promoter Using Gibson Assembly

Gibson assembly (GA) cloning offers a rapid, reliable, and flexible alternative to conventional DNA cloning methods. We used GA to create customized plasmids for expression of exogenous genes in mouse embryonic stem cells (mESCs). Expression of exogenous genes under the control of the SV40 or human cytomegalovirus promoters diminishes quickly after transfection into mESCs. A remedy for this diminished expression is to use the human elongation factor-1 alpha (hEF1&#945;) promoter to drive gene expression. Plasmid vectors containing hEF1&#945; are not as widely available as SV40- or CMV-containing plasmids, especially those also containing N-terminal 3xFLAG-tags. The protocol described here is a rapid method to create plasmids expressing FLAG-tagged CstF-64 and CstF-64 mutant under the expressional regulation of the hEF1&#945; promoter. GA uses a blend of DNA exonuclease, DNA polymerase and DNA ligase to make cloning of overlapping ends of DNA fragments possible. Based on the template DNAs we had available, we designed our constructs to be assembled into a single sequence. Our design used four DNA fragments: pcDNA 3.1 vector backbone, hEF1&#945; promoter part 1, hEF1&#945; promoter part 2 (which contained 3xFLAG-tag purchased as a double-stranded synthetic DNA fragment), and either CstF-64 or specific CstF-64 mutant. The sequences of these fragments were uploaded to a primer generation tool to design appropriate PCR primers for generating the DNA fragments. After PCR, DNA fragments were mixed with the vector containing the selective marker and the GA cloning reaction was assembled. Plasmids from individual transformed bacterial colonies were isolated. Initial screen of the plasmids was done by restriction digestion, followed by sequencing. In conclusion, GA allowed us to create customized plasmids for gene expression in 5 days, including construct screens and verification.

Synthesis of custom plasmids is labor and time consuming. This protocol describes the use of Gibson assembly cloning to reduce the work and duration of custom DNA cloning procedure. The protocol described also produces reliable tagged protein constructs for mammalian expression at similar cost to the traditional cut-and-paste DNA cloning.

Gibson assembly (GA) cloning offers a rapid, reliable, and flexible alternative to conventional DNA cloning methods. We used GA to create customized ...

Filtration Isolation of Nucleic Acids:  A Simple and Rapid DNA Extraction Method

FINA, filtration isolation of nucleic acids, is a novel extraction method which utilizes vertical filtration via a separation membrane and absorbent pad to extract cellular DNA from whole blood in less than 2 min. The blood specimen is treated with detergent, mixed briefly and applied by pipet to the separation membrane. The lysate wicks into the blotting pad due to capillary action, capturing the genomic DNA on the surface of the separation membrane. The extracted DNA is retained on the membrane during a simple wash step wherein PCR inhibitors are wicked into the absorbent blotting pad. The membrane containing the entrapped DNA is then added to the PCR reaction without further purification. This simple method does not require laboratory equipment and can be easily implemented with inexpensive laboratory supplies. Here we describe a protocol for highly sensitive detection and quantitation of HIV-1 proviral DNA from 100 &#181;l whole blood as a model for early infant diagnosis of HIV that could readily be adapted to other genetic targets.

We describe here a simple and rapid paper-based DNA extraction method of HIV proviral DNA from whole blood detected by quantitative PCR. This protocol can be extended for use in detecting other genetic markers or using alternative amplification methods.

FINA, filtration isolation of nucleic acids, is a novel extraction method which utilizes vertical filtration via a separation membrane and absorbent pad ...