This work was supported by the grant from the National Natural Science Foundation of China No. 81670269, No. 81500355 and No. 81500226.

This study was approved by the Central South University Ethics Committee for Animal Research from The Second Xiangya Hospital (Changsha, China). The manuscript was prepared according to ARRIVE (Animal Research: Reporting of In Vivo Experiments) guidelines12.
1. Material and animal
<ol>
	<li>Prepare required materials: 75% ethanol, adhesive tape, epilating agent, 2 mL tube, 1.0 mL syringe connected with needle (26G), electronic scale, heparin and saline (see Table of Materials).</li>
	<li>Animals: Prepare 10 Kunming mice, 6-8 weeks old and weighing 21.6-28.3&#160;g (see Table of Materials). Maintain mice in accordance with the Guide for the Care and Use of Laboratory Animals13.</li>
</ol>
2. Anesthesia and animal positioning
<ol>
	<li>Weigh the mouse to calculate the required dosage of anesthetic agent.</li>
	<li>Inject sodium pentobarbital (60 mg/kg) through intraperitoneal injection to induce general anesthesia14 (Figure 1). Apply a sterile eye lubrication ointment at the start of the procedure to prevent damage to exposed eyes. 
	NOTE: Mice are considered to be sufficiently anesthetized when showing no motor response to testing of the pedal withdrawal reflex, tail pinch, or abdominal skin pinch.</li>
	<li>Place the mouse in the operation table in a supine position and 2-4 cm away from the edge of the table to facilitate vein puncture (Figure 2). Fix the limbs in a comfortable position as shown in Figure 2. No intubation or mechanical ventilation is needed in the whole procedure.</li>
	<li>Apply epilating agent around the infraclavicular space with a cotton swab.</li>
	<li>Three minutes later, wash the epilating agent with a wet cotton swab to remove the fur and any visible dirt.</li>
	<li>Sterilize the infraclavicular space with 75% ethanol and then dry with clean gauze.</li>
</ol>
3. Subclavian vein puncture and blood collection
<ol>
	<li>Identify the location of the clavicle bone and superior sternal fossa with a finger.</li>
	<li>Locate the puncture site close to the middle of the clavicle bone and caudal to it. Put the left index finger lateral to the puncture site to fix the skin and subcutaneous tissue (Figure 3).</li>
	<li>Move the needle upward and cranially toward the superior sternal fossa. Once the needle enters the subcutaneous tissue, move the ring finger of the right hand backward to form negative pressure (Figure 3). 
	NOTE: During this step, the position of the operator&#180;s right hand should be slightly lower than the operation table to make the needle move upward and superior to the horizontal plane. That is why the animal is placed near the edge of the table.</li>
	<li>Move the syringe forward 3-4 mm but stop if there is no blood drain into the syringe. Then slowly draw back the syringe and keep negative pressure in it. In most occasions, the blood would enter the syringe when drawing back.</li>
	<li>Once the blood enters the syringe, fix the syringe and maintain negative pressure until the required volume (200 &#181;L) of blood is collected in the syringe.</li>
	<li>After blood collection, withdraw the puncture needle, and press the puncture site with a cotton swab slightly for 1-2 minutes to stop bleeding. Then, return mice to the cage. 
	NOTE: Occasionally, one could not obtain the blood at his/her first attempt. Adjust the direction of the needle laterally and repeat steps 3.3-3.5. If 3 attempts fail to obtain blood sample, switch to the other side.</li>
	<li>Transfer the blood sample into a heparinized tube.</li>
</ol>
4. Mice recovery
<ol>
	<li>While the pentobarbital anesthesia is in effect, speed recovery by providing heat support until the mouse is moving again.</li>
</ol>

<ol>
	<li>McCosh, R. B., Kreisman, M. J., Breen, K. M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Frequent+Tail-tip+Blood+Sampling+in+Mice+for+the+Assessment+of+Pulsatile+Luteinizing+Hormone+Secretion.">Frequent Tail-tip Blood Sampling in Mice for the Assessment of Pulsatile Luteinizing Hormone Secretion.</a> Journal of Visualized Experiments. (137), (2018).</li><li>Regan, R. D., Fenyk-Melody, J. E., Tran, S. M., Chen, G., Stocking, K. L. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Comparison+of+Submental+Blood+Collection+with+the+Retroorbital+and+Submandibular+Methods+in+Mice+(Mus+musculus).">Comparison of Submental Blood Collection with the Retroorbital and Submandibular Methods in Mice (Mus musculus).</a> Journal of the American Association for Laboratory Animal Science. 55 (5), 570-576 (2016).</li><li>Park, A. Y., 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=Blood+collection+in+unstressed,+conscious,+and+freely+moving+mice+through+implantation+of+catheters+in+the+jugular+vein:+a+new+simplified+protocol.">Blood collection in unstressed, conscious, and freely moving mice through implantation of catheters in the jugular vein: a new simplified protocol.</a> Physiological Reports. 6 (21), e13904 (2018).</li><li>Heimann, M., Kasermann, H. P., Pfister, R., Roth, D. R., Burki, K. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+collection+from+the+sublingual+vein+in+mice+and+hamsters:+a+suitable+alternative+to+retrobulbar+technique+that+provides+large+volumes+and+minimizes+tissue+damage.">Blood collection from the sublingual vein in mice and hamsters: a suitable alternative to retrobulbar technique that provides large volumes and minimizes tissue damage.</a> Laboratory Animals. 43 (3), 255-260 (2009).</li><li>Parasuraman, S., Raveendran, R., Kesavan, R. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Blood+sample+collection+in+small+laboratory+animals.">Blood sample collection in small laboratory animals.</a> Journal of Pharmacology &amp; Pharmacotherapeutics. 1 (2), 87-93 (2010).</li><li>Diehl, K. H., 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=A+good+practice+guide+to+the+administration+of+substances+and+removal+of+blood,+including+routes+and+volumes.">A good practice guide to the administration of substances and removal of blood, including routes and volumes.</a> Journal of Applied Toxicology. 21 (1), 15-23 (2001).</li><li>van Herck, H., 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=Orbital+sinus+blood+sampling+in+rats+as+performed+by+different+animal+technicians:+the+influence+of+technique+and+expertise.">Orbital sinus blood sampling in rats as performed by different animal technicians: the influence of technique and expertise.</a> Laboratory Animals. 32 (4), 377-386 (1998).</li><li>Tsai, P. P., 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=Effects+of+different+blood+collection+methods+on+indicators+of+welfare+in+mice.">Effects of different blood collection methods on indicators of welfare in mice.</a> Lab Anim (NY). 44 (8), 301-310 (2015).</li><li>Holmberg, H., Kiersgaard, M. K., Mikkelsen, L. F., Tranholm, M. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Impact+of+blood+sampling+technique+on+blood+quality+and+animal+welfare+in+haemophilic+mice.">Impact of blood sampling technique on blood quality and animal welfare in haemophilic mice.</a> Laboratory Animals. 45 (2), 114-120 (2011).</li><li>Yang, H., 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=Safety+and+efficacy+of+a+modified+axillary+vein+technique+for+pacemaker+implantation.">Safety and efficacy of a modified axillary vein technique for pacemaker implantation.</a> Cardiology Plus. 3, 104-107 (2018).</li><li>Yang, H., 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=Subclavian+Vein+Puncture+As+an+Alternative+Method+of+Blood+Sample+Collection+in+Rats.">Subclavian Vein Puncture As an Alternative Method of Blood Sample Collection in Rats.</a> Journal of Visualized Experiments. (141), (2018).</li><li>Kilkenny, C., Altman, D. G. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Improving+bioscience+research+reporting:+ARRIVE-ing+at+a+solution.">Improving bioscience research reporting: ARRIVE-ing at a solution.</a> Laboratory Animals. 44 (4), 377-378 (2010).</li><li>Research, I. f. L. A. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=.">.</a> Guide for the care and use of laboratory animals. , (1996).</li><li>Redel, 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=Impact+of+ischemia+and+reperfusion+times+on+myocardial+infarct+size+in+mice+in+vivo.">Impact of ischemia and reperfusion times on myocardial infarct size in mice in vivo.</a> Experimental Biology and Medicine (Maywood, N.J.). 233 (1), 84-93 (2008).</li><li>Tsukamoto, A., Serizawa, K., Sato, R., Yamazaki, J., Inomata, T. <a target="_blank" href="http://www.ncbi.nlm.nih.gov/entrez/query.fcgi?db=PubMed&cmd=Search&doptcmdl=Citation&defaultField=Title+Word&term=Vital+signs+monitoring+during+injectable+and+inhalant+anesthesia+in+mice.">Vital signs monitoring during injectable and inhalant anesthesia in mice.</a> Experimental Animals. 64 (1), 57-64 (2015).</li><li>Zou, W., 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=Repeated+Blood+Collection+from+Tail+Vein+of+Non-Anesthetized+Rats+with+a+Vacuum+Blood+Collection+System.">Repeated Blood Collection from Tail Vein of Non-Anesthetized Rats with a Vacuum Blood Collection System.</a> Journal of Visualized Experiments. (130), (2017).</li></ol>

None declared.

This report represents an extension of previous research on blood sampling through the subclavian vein puncture in rats11. As the mouse is the most commonly used research animal, it would be valuable to see if this technique can also be applied to mice. The challenge comes from the relatively smaller diameter of the subclavian vein.
In the present research, we found that subclavian puncture in mice is a feasible and reliable way to collect blood. Compared to the conventional methods such as tail vein cutting or orbital blood collection, there are no ethical issues of the present method. All animals survived after this procedure without liquid supplements after around 200 &#181;L of blood extraction, and animals could be used for further experimental studies. Theoretically, the total sample volume extraction could not reach more than 10% of total circulating blood volume each time and the total volume of an adult animal is 55 to 70 mL/kg body weight5. For the mice used in this research (21.6-28.3 g), the maximum volume extraction should be around 200 &#181;L. We thus set the blood sampling amount around 200 &#181;L for each mouse. The inability to measure blood pressure, heart rate, and other stress parameters are the main limitations of this report.
Sufficient general anesthesia is another important issue to guarantee the success of the puncture. The mice should remain quiet during the puncture procedure to avoid the risk of injuring the vessel by the needle. We found that pentobarbital sodium at 60 mg/kg for general anesthesia could satisfy ideal depth of anesthesia. A downside of this agent is the relatively long recovery time (averaging about 30 minutes). In some institutes, isoflurane inhalation is used for the short recovery time and should be taken into consideration as an alternative anesthesia choice15.
The location of subclavian vein is shown in Figure 4. Because of the thin wall and low pressure in the vein, the anterior and posterior wall of the subclavian vein would attach to each other under the pressure of a needle while the needle is moving forward (Figure 5A). While withdrawing the plunger slowly backwards, the attached walls will separate spontaneously, and the tip of needle could enter the true cavity of vessel and blood could drain into the syringe under sustained negative pressure (Figure 5B). Use of a vacuum blood collection system16 might also favor the blood collection. Due to the relatively small diameter of the mice subclavian vein, there can be failures even for an experienced operator. For a novice, we recommend subclavian vein puncture in rats as reported11. After several successful puncture attempts in rats, the success rate of subclavian vein puncture in mice could be significantly enhanced. Make sure that the exact puncture location is just caudal to the middle of the clavicle bone. The needle moving upward and cranial to the superior sternal fossa are other key points to guarantee a successful puncture.
In conclusion, subclavian vein puncture is a safe and effective method for blood collection in mice. Besides tail vein cutting and retro-orbital plexus blood collection, this method is feasible, safe, and suitable for observational researches at several time points in mice.

Blood sample collection from mice is essential in most research laboratories. The conventional approaches for blood collection in mice is tail cutting when less than 100 &#181;L of sample is needed1. However, if more than 100 &#181;L of blood are required at a nonterminal time point, retroorbital, submandibular bleeding or submental blood collection are the most commonly considered techniques2. In some occasions, the jugular vein catheterization through a surgical incision was adopted as an alternative method3. 
Nevertheless, the above methods are harmful to the mice. To the best of our knowledge, the retroorbital method is not widely accepted because of the potential risk of complications4,5. Operation related trauma not only happens in the visible area6,7, but also deep within the orbit6. Besides, submandibular blood collection is stressful8 and might be associated with excessive bleeding2,9. Based on our prior research10,11, here we introduce a new strategy for blood collection from the subclavian vein in mice. The safety, feasibility, and obtained blood volume with this technique are presented and discussed.

<table border="0" cellpadding="0" cellspacing="0" style="width:1143px;" width="1144">
	<tbody>
		<tr height="21">
			<td height="21" style="height:21px;width:374px;">1.0 mL syringe</td>
			<td style="width:576px;">Shandong Weigao Group Medical Polymer Co., Ltd (Weihai, Shandong Province, China)</td>
			<td style="width:130px;">20163151593</td>
			<td style="width:64px;"></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">75% ethanol</td>
			<td>Department of Pharmacy, The Second Xiangya Hospital of Central South University</td>
			<td colspan="2">made in Department of Pharmacy,The Second Xiangya Hospital of Central South Univesity</td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">adhesive tape</td>
			<td>3M Deutschland GmbH (Kamen, Germany)</td>
			<td>1534-1</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">canvas gloves</td>
			<td>for anesthesia</td>
			<td></td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">electronic scale</td>
			<td>Dongguan Shengheng Electronics Co. Ltd (Dongguan, Guangdong Province, China)</td>
			<td>KP-3000</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">epilating agent</td>
			<td>France Yi Sha Cosmetics Co. Ltd (Guangzhou, Guangdong Province, China)</td>
			<td>8281744</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">heparin (used concentration 10 U/mL, 2 mL, 12500 IU)</td>
			<td>Nanjing Xinbai Pharmaceutical Co. Limited (Nanjing, Jiangsu Province, China)</td>
			<td>H32025851</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">mice</td>
			<td>Hunan SJA Laboratory Animal Co. Ltd (Changsha, Hunan Province, China)&#160;</td>
			<td>Kunming spcies</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">needle, 26G, 0.45 mm x 16 mm</td>
			<td>Shandong Weigao Group Medical Polymer Co. Ltd (Weihai, Shandong Province, China)</td>
			<td>20163151593</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">pentobarbital sodium (used solution 1%)</td>
			<td>Merck</td>
			<td>P-010-1ML</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">physiological saline, 100 mL</td>
			<td>Hunan Kelun Pharmaceutical Co. Ltd (Yueyang, Hunan Province,China)</td>
			<td>H43020454</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">stastical software</td>
			<td>International Business Machines</td>
			<td>SPSS Statistics 25</td>
			<td></td>
		</tr>
		<tr height="21">
			<td height="21" style="height:21px;">tube, 2 mL</td>
			<td>Hubei Jinxing Technology &#38; Development Co. Ltd (Wuhan Hubei Province, China)</td>
			<td>MCT-150-C</td>
			<td></td>
		</tr>
	</tbody>
</table>

blood collection through subclavian vein puncture in mice

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in research work. Tail blood collection is a popular method when a small amount of blood sample is needed. Orbital artery could be considered if a large amount of blood is needed but this blood collection method has ethical issues. Formerly, we demonstrated the feasibility and safety of blood sample collection through subclavian vein puncture in rats, and here we investigate whether this method could be used in mice. We report that this method is safe and practical for blood collection in mice. Blood collection through the subclavian vein puncture in mice can be a convenient method in daily research works.

We repeated this procedure in 10 Kunming mice (male n = 5, female n = 5, weight 25.4 &#177; 2.0 g). Nine procedures succeeded on the right side. One case failed within 3 attempts in the right side and blood collection succeeded on the left side. The time course (from puncture to obtaining required blood volume) ranged between 35-126 seconds (average 68.4 &#177; 26.4 s). Blood collection volume was set to around 200 &#181;L (average 203 &#177; 11.6 &#181;L). Blood collection succeeded within 1 to 4 attempts. Blood sampling succeeded on the first attempt in two mice and after 4 attempts in one mouse; the sampling took 2-3 attempts in the other mice. All data were illustrated in Table 1. All animals survived and recovered within 30 minutes after the blood sampling. There was no significant difference between sexes for all observed parameters (Table 1).
<img alt="Figure 1" class="xfigimg" src="/files/ftp_upload/59556/59556fig1.jpg" /> 
Figure 1: General anesthesia through intraperitoneal injection <a href="https://www.jove.com/files/ftp_upload/59556/59556fig1large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 2" class="xfigimg" src="/files/ftp_upload/59556/59556fig2.jpg" /> 
Figure 2: The supine position of mouse. Note the distance between margin and mouse is 2-4 cm. <a href="https://www.jove.com/files/ftp_upload/59556/59556fig2large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 3" class="xfigimg" src="/files/ftp_upload/59556/59556fig3.jpg" /> 
Figure 3: The puncture site and posture of operator&#39;s hands. Note that the ring finger of right hand moves backward to form negative pressure. The left hand is placed lateral to the puncture site to fix the skin and subcutaneous tissues. <a href="https://www.jove.com/files/ftp_upload/59556/59556fig3large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 4" class="xfigimg" src="/files/ftp_upload/59556/59556fig4.jpg" /> 
Figure 4: The location of the subclavian vein, clavicle bone and superior sternal fossa. The subclavian vein courses beneath the clavicle bone and drains into the superior vena cava under the superior sternal fossa. <a href="https://www.jove.com/files/ftp_upload/59556/59556fig4large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<img alt="Figure 5" class="xfigimg" src="/files/ftp_upload/59556/59556fig5.jpg" /> 
Figure 5: The relation between the vessel wall and needle during the procedure. (A) The walls of the subclavian vein attach to each other as the needle moves forward, so no blood could be drawn out. (B) While withdrawing the needle backward, the walls separate from each other and the blood could be drawn out. <a href="https://www.jove.com/files/ftp_upload/59556/59556fig5large.jpg" target="_blank">Please click here to view a larger version of this figure.</a>
<table border="1" fo:keep-together.within-page="1" fo:keep-with-next.within-page="always">
	<tbody>
		<tr>
			<td>variable</td>
			<td>Total (n=10)</td>
			<td>Male (n=5)</td>
			<td>Female (n=5)</td>
			<td>P Value</td>
		</tr>
		<tr>
			<td>Body Weight (g)</td>
			<td>25.3 &#177; 2.2</td>
			<td>25.3 &#177; 3.0</td>
			<td>25.4 &#177; 1.3</td>
			<td>0.926</td>
		</tr>
		<tr>
			<td>Blood Volume (&#956;L)</td>
			<td>203.0 &#177; 11.6</td>
			<td>208 &#177; 13.0</td>
			<td>198 &#177; 8.4</td>
			<td>0.187</td>
		</tr>
		<tr>
			<td>Time Course (s)</td>
			<td>68.4 &#177; 26.4</td>
			<td>70.6 &#177; 35.1</td>
			<td>66.2 &#177; 18.0</td>
			<td>0.809</td>
		</tr>
		<tr>
			<td>Withdrawals</td>
			<td>2.3 &#177; 0.9</td>
			<td>2.4 &#177; 1.1</td>
			<td>2.2 &#177; 0.8</td>
			<td>0.760</td>
		</tr>
		<tr>
			<td colspan="4">There were no significant sex differences for all observed parameters, all P value &#62;0.05.</td>
			<td></td>
		</tr>
	</tbody>
</table>
Table 1: Observed parameters between the sexes

Watch this Scientific Journal Video about Blood Collection Through Subclavian Vein Puncture in Mice at JoVE.com

Blood Collection Through Subclavian Vein Puncture in Mice

Here, we present a protocol to take blood samples from the subclavian vein of mice.

The mouse is the foremost mammalian model for studying human disease and human health. However, blood sample collection from mice is challenging in ...

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34.3K Views.  Central South University. Here, we present a protocol to take blood samples from the subclavian vein of mice.

Video: Blood Collection Through Subclavian Vein Puncture in Mice

Repeated Blood Collection from Tail Vein of Non-Anesthetized Rats with a Vacuum Blood Collection System

Blood can be collected from rats in a number of sampling locations. For instance, the tail vein is a superior location for blood sampling. However, the tail vein is thin so that it is sometimes hard to puncture. In addition, the tail vein has low blood flow and requires a long sampling time to get sufficient blood. The present report describes a simple blood sampling method, the vacuum blood collection method, which is usually used to obtain blood samples from patients, here used for non-anesthetized rats. The 22 G butterfly needle tip was inserted into one of the lateral tail veins approximately 2-3 cm from the tip of the tail at an angle of approximately 20&#176;, and blood was collected in the vacuum collection tube by inserting the rubber end of the butterfly needle into the vacuum blood collection tube. The present experimental results show that the success rate was 95% in the experimental group and 90% in the beginner group. The success rate and puncture times were similar between two groups. The sampling duration was significantly shorter in the experimental group compared to beginner group. In conclusion, this vacuum blood collection method for sequential blood sampling from the tail vein of non- anesthetized rats is feasible and easy-to-learn, which might serve as a reliable alternative to other conventionally used blood sampling techniques for rats.

Here, we describe a simple tail vein blood sampling method in non-anesthetized rats using a vacuum extraction tube system. This method reduces the risk of direct exposure to blood and simplifies taking multiple samples from a single venipuncture.

Blood can be collected from rats in a number of sampling locations. For instance, the tail vein is a superior location for blood sampling. However, the ...

Subclavian Vein Puncture As an Alternative Method of Blood Sample Collection in Rats

Blood collection with enough blood volume is essential in animal experiments. Blood collection from the tail vein of rats is popular and less stressful compared to other more aggressive methods such as retro-orbital plexus sample collection. However, this blood collection method is sometimes limited by an unsatisfactory success rate. Here, we introduce a method for blood collection through the subclavian vein puncture. The subclavian vein is located just under the clavicle and this vein is large enough to fulfill the volume requirements of blood collection. Our results show that this method is safe and applicable for blood collection sampling with the required blood volume. Blood collection through the subclavian vein puncture could serve as an alternative blood collection method in case of failed tail vein blood sampling in rats.

Here, we present a protocol to collect blood samples from the rat subclavian vein.

Blood collection with enough blood volume is essential in animal experiments. Blood collection from the tail vein of rats is popular and less stressful ...

Simultaneous Flow Cytometric Characterization of Multiple Cell Types Retrieved from Mouse Brain/Spinal Cord Through Different Homogenization Methods

Recent advances in viral vector and nanomaterial sciences have opened the way for new cutting-edge approaches to investigate or manipulate the central nervous system (CNS). However, further optimization of these technologies would benefit from methods allowing rapid and streamline determination of the extent of CNS and cell-specific targeting upon administration of viral vectors or nanoparticles in the body. Here, we present a protocol that takes advantage of the high throughput and multiplexing capabilities of flow cytometry to allow a straightforward quantification of different cell subtypes isolated from mouse brain or spinal cord, namely microglia/macrophages, lymphocytes, astrocytes, oligodendrocytes, neurons and endothelial cells. We apply this approach to highlight critical differences between two tissue homogenization methods in terms of cell yield, viability and composition. This could instruct the user to choose the best method depending on the cell type(s) of interest and the specific application. This method is not suited for analysis of anatomical distribution, since the tissue is homogenized to generate a single-cell suspension. However, it allows to work with viable cells and it can be combined with cell-sorting, opening the way for several applications that could expand the repertoire of tools in the hands of the neuroscientist, ranging from establishment of primary cultures derived from pure cell populations, to gene-expression analyses and biochemical or functional assays on well-defined cell subtypes in the context of neurodegenerative diseases, upon pharmacological treatment or gene therapy.

We present a flow cytometry method to identify simultaneously different cell types retrieved from mouse brain or spinal cord. This method could be exploited to isolate or characterize pure cell populations in neurodegenerative diseases or to quantify the extent of cell targeting upon in vivo administration of viral vectors or nanoparticles.

Recent advances in viral vector and nanomaterial sciences have opened the way for new cutting-edge approaches to investigate or manipulate the central ...

Minimizing Post-Infusion Portal Vein Bleeding during Intrahepatic Islet Transplantation in Mice

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the kidney capsule in most rodent preclinical islet transplantation studies. This model is commonly used because murine intrahepatic islet transplantation is technically challenging, and a high percentage of mice could die from surgical complications, especially bleeding from the injection site post-transplantation. In this study, two procedures that can minimize the incidence of post-infusion portal vein bleeding are demonstrated. The first method applies an absorbable hemostatic gelatin sponge to the injection site, and the second method involves penetrating the islet injection needle through the fat tissue first and then into the portal vein by using the fat tissue as a physical barrier to stop bleeding. Both methods could effectively prevent bleeding-induced mouse death. The whole liver section showing islet distribution and evidence of islet thrombosis post-transplantation, a typical feature for intrahepatic islet transplantation, were presented. These improved protocols refine the intrahepatic islet transplantation procedures and may help laboratories set up the procedure to study islet survival and function in pre-clinical settings.

Here we present refined surgical procedures on successfully performing intraportal islet transplantation, a clinically relevant but technically challenging surgical procedure, in mice.

Although the liver is currently accepted as the primary transplantation site for human islets in clinical settings, islets are transplanted under the ...

Repetitive Blood Sampling from the Subclavian Vein of Conscious Rat

Rats are widely used in pharmacokinetics (PK) and toxicokinetic (TK) studies that need to collect a certain amount of blood at specific time points to detect drug exposure. The rat blood sampling method determines the quality of the plasma and further affects the precision of the test results. The subclavian vein blood collection method described in this protocol collects blood samples repeatedly in the conscious state of animals to meet the needs of PK and TK tests. The skills of restraint handling and appropriate procedure of needle incision ensure the success rate of blood collection. It is easy to operate while ensuring the quality of plasma and at the same time catering to animal welfare. However, this method requires skilled operation, and an improper one may cause animal weakness, pain, lameness, and even mortality. The current method has been used in the testing facility for a 4-week oral toxicity study in Sprague Dawley (SD) rats with TK. The maximum amount of blood collected within 24 h did not exceed 20% of the animal's total blood. The animals' body weight was more than 200 g for males and females. The data showed that the animals' bodyweight increased steadily every week, and the clinical observation was normal after repetitive sample collection.

The present protocol describes a simple and efficient method for collecting blood from the subclavian vein in rats. It enables rapid, timely, and easily identifiable sampling without anesthesia and obtains high-quality blood through repetitive sample collection.

Rats are widely used in pharmacokinetics (PK) and toxicokinetic (TK) studies that need to collect a certain amount of blood at specific time points to ...

Comparative Study of Blood Collection Techniques in Rats

Modified Tail Vein and Penile Vein Puncture for Blood Sampling in the Rat Model

Blood samples are required in most experimental animal designs to assess various hematological parameters. This paper presents two procedures for blood collection in rats: the lateral tail vein puncture and the dorsal penile vein puncture, which offer significant advantages over other previously described techniques. This study shows that these two procedures allow for fast sampling (under 10 min) and yield sufficient blood volumes for most assays (202 &#956;L &#177; 67.7 &#956;L). The dorsal penile vein puncture must be done under anesthesia, whereas the lateral tail vein puncture can be done on a conscious, restrained animal.
Alternating these two techniques, therefore, enables blood draw in any situation. While it is always recommended for an operator to be assisted during a procedure to ensure animal welfare, these techniques require only a single operator, unlike most blood sampling methods that require two. Moreover, whereas these previously described methods (e.g., jugular stick, subclavian vein blood draw) require extensive prior training to avoid harm to or death of the animal, tail vein and dorsal penile vein puncture are rarely fatal. For all these reasons, and according to the context (e.g., for studies including male rats, during the perioperative or immediate postoperative period, for animals with thin tail veins), both techniques can be used alternately to enable repeated blood draws.

Author Spotlight: Context Dependent Blood Collection Methods in Rats 

Here, we present a protocol to offer rapid, easy, and reliable blood collection alternatives for the rat model. We describe three different blood sampling methods according to the context: tail vein puncture under anesthesia or on a conscious animal, and dorsal penile vein puncture under anesthesia.

Blood samples are required in most experimental animal designs to assess various hematological parameters. This paper presents two procedures for blood ...

Subclavian Vein Puncture Method for Repeated Blood Collection in Conscious Rats

Subclavian Vein Blood Sampling in Conscious Rats

There are several established methods for obtaining repeated blood samples from rats, with the most commonly employed methods being lateral tail vein sampling without anesthesia and jugular vein sampling with anesthesia. However, most of these methods require assistance and anesthetic equipment and sometimes pose difficulties in terms of blood collection or the poor quality of blood samples. In addition, these methods of blood collection consume significant time and human resources when repeated blood sampling is required for a large number of rats. This study presents a technique for repetitive blood sampling in non-anesthetized rats by a single proficient individual. Highly satisfactory blood samples can be obtained by puncturing the subclavian vein. The method demonstrated an impressive overall success rate of 95%, with a median time of merely 2 min from rat restraint to the completion of blood collection. Furthermore, performing consecutive blood collections within the designated range does not inflict any harm on the rats. This method is worth promoting for blood collection, especially in large-scale pharmacokinetic studies.

Author Spotlight: Developing an Efficient Blood Collection Method in Non-Anesthetized Rats 

Here we present a combination of effective rat restriction and subclavian vein puncture methods that enable rapid, safe, and repeated blood collection in rats without anesthesia.

There are several established methods for obtaining repeated blood samples from rats, with the most commonly employed methods being lateral tail vein ...

Blood and Tissue Collection from Rats After Tuina Therapy

Puncture Wound Hemostasis and Montaged Electron Microscopy 

Puncture Wound Hemostasis and Preparation of Samples for Montaged Wide-Area Electron Microscopy Analysis

Hemostasis, the process of normal physiological control of vascular damage, is fundamental to human life. We all suffer minor cuts and puncture wounds from time to time. In hemostasis, self-limiting platelet aggregation leads to the formation of a structured thrombus in which bleeding cessation comes from capping the hole from the outside. Detailed characterization of this structure could lead to distinctions between hemostasis and thrombosis, a case of excessive platelet aggregation leading to occlusive clotting. An imaging-based approach to puncture wound thrombus structure is presented here that draws upon the ability of thin-section electron microscopy to visualize the interior of hemostatic thrombi. The most basic step in any imaging-based experimental protocol is good sample preparation. The protocol provides detailed procedures for preparing puncture wounds and platelet-rich thrombi in mice for subsequent electron microscopy. A detailed procedure is given for in situ fixation of the forming puncture wound thrombus and its subsequent processing for staining and embedding for electron microscopy. Electron microscopy is presented as the end imaging technique because of its ability, when combined with sequential sectioning, to visualize the details of the thrombus interior at high resolution. As an imaging method, electron microscopy gives unbiased sampling and an experimental output that scales from nanometer to millimeters in 2 or 3 dimensions. Appropriate freeware electron microscopy software is cited that will support wide-area electron microscopy in which hundreds of frames can be blended to give nanometer-scale imaging of entire puncture wound thrombi cross-sections. Hence, any subregion of the image file can be placed easily into the context of the full cross-section.

Author Spotlight: Revealing Platelet Dynamics Through Advances in Structural Hematology

A puncture wound procedure for hemostatic thrombus formation is presented here. The formed thrombi are large and are hundreds of microns in diameter. Hence, volume imaging approaches are appropriate. We suggest montaged wide-area transmission electron microscopy as a high-resolution approach available to many and detail a preparative protocol.

Hemostasis, the process of normal physiological control of vascular damage, is fundamental to human life. We all suffer minor cuts and puncture wounds ...

AAV-Based Therapies via Intravenous Injection in Preclinical Mouse Models

Consistent Delivery of Adeno-Associated Virus via Lateral Tail-Vein Injection in Adult Mice

Many disorders affect multiple organs or involve different regions of the body, so it is critical to deliver therapeutics systemically to target the affected cells located in different sites. Intravenous injection is a widely used systemic delivery route in preclinical studies that assess treatments intended for body-wide administration. In adult mice, it involves the intravenous administration of the therapeutic agent into the mouse&#39;s lateral tail veins. When mastered, tail-vein injections are safe and fast, and only require simple and commonly available tools. However, tail-vein injections are technically challenging and require extensive training and continuous practice to ensure the accurate delivery of the intended dose.
Here we describe a detailed, optimized, lateral tail-vein injection protocol that we have developed based on our experience and on recommendations that had been previously reported by other groups. Other than the mouse restrainers and insulin syringes, this protocol requires only reagents and equipment that are readily available in most labs. We found that following this protocol results in consistently successful intravenous delivery of adeno-associated virus (AAV) into the tail veins of unsedated 7-9 week-old mice. Additionally, we describe the optimized protocols for the histological detection of fluorescent reporter proteins and vector genome per diploid genome (vg/dg) quantification used to assess AAV transduction and biodistribution. The goal of this protocol is to aid experimenters in easily performing tail-vein injections successfully and consistently, which can reduce the practice time needed to master the technique.

Author Spotlight: Developing Gene Therapies for Muscular Dystrophies and Neuromuscular Disorders

Here we detail an optimized protocol for mouse lateral tail-vein injection to systemically administer adeno-associated virus (AAV) in adult mice. Additionally, we describe protocols of commonly used assays to assess AAV transduction.

Many disorders affect multiple organs or involve different regions of the body, so it is critical to deliver therapeutics systemically to target the ...

Methods Article

Blood Collection Through Subclavian Vein Puncture in Mice