Light arc for tail vein injection is a novel technique that is used to administer drug substances to black strains of rodents. The black strains of rodents have a darker tail which makes it difficult to spot the caudal vein due to color contrast. This illumination problem is solved by Conductscience’s Light Arc which distributes a uniform light over an angle of 180° around the subject’s tail.
Our apparatus consists of a light arc that stands on a flat base connected to the power source. A Broome style handler is placed in the center for restraining the subject. The arc is equipped with 10 RGB LED, approx. one every 2cm. The color contrast is regulated by the intensity of the primary colors; it can be adjusted with red, green, and blue knobs for the optimal contrast of the veins.
The standard procedure for intravenous injections in subjects utilizing Conductscience’s Light Arc is as follows:
- Weigh the subject and determine the volume of drug to be administered.
- The light color is adjusted to meet the best contrast of the caudal vein.
- Fill the syringe with the drug under consideration and remove air bubbles that may evolve.
- Critical: The injection must not be cold, administering large quantities of the cold solution may cause hypothermia which may alter the efficacy of the drug under consideration.
- Carefully introduce the subject into the Broome handler. (Refer to Broome handler’s protocol section for detailed instructions).
- After restraining the subject, immerse its tail in the warm water bath set at 42°C for approx. 40 to 45 seconds for vasodilation. Note: A beaker should be placed in the water bath to restrict the contamination by urine and feces. Furthermore, warming up the whole subject by heat lamps may prove to be more efficient, but it takes longer and carries a risk of heatstroke.
- Dry the tail and try to locate the left or right caudal vein. The restrainer is fixed to the stand at an angle of 90° so that the chosen caudal vein faces the experimenter.
- The tail should then be held with the thumb of one hand, and the needle should be inserted gently with the preferred hand. Note: The needle should be parallel to the vein; almost a 0° angle, and should not be penetrated more than 6-7mm inside. Critical: Do not attempt to extract the blood back into the needle as this may cause the vein to rupture.
- The plunger should be push be pressed gently and slowly. Critical: If you feel resistance or see a lump, immediate stop and retract the needle. Insert the needle approx. 1 to 2 cm above the same vein.
- Cover the injection site with a swab before retracting the needle to limit excessive blood and drug loss. Keep pressing the swab until you remove the subject from the restrainer.
- Rinse the restrainer with a sufficient quantity of water before injecting the next subject.
- Ideal for Large Quantity Samplings
- Produced with High Quality Acrylic
- Transparent, Durable and Easy to Clean
- Mouse: 10.2 cm Diameter, 14.6 cm length
- Rat: 14cm Diameter, 17cm Length
Advancements in biomedical and pharmacological research necessitate the use of intravenous or I.V. injections, the primary choice for parenteral administration of particular drugs or substances for experimental analysis and examination. I.V. injections are highly advantageous methods because they ensure quick and complete bioavailability of the drug candidate in blood circulation (Messer, 2015). In rodents, intravenous injections are usually done through the lateral tail veins. Vein visibility, however, is a crucial factor in successful I.V. procedures and is often a concern particularly for black rodent strains. The illumination devices have become essential in effectively discerning target veins in the rodent tail.
The light arc (Messer, 2015) is a novel device that aids in drug administration procedures through intravenous injections among black strains of rodents. The black strains of rodents have darker tails, making it difficult in spotting the caudal vein due to poor color contrast. The light arc succeeds in addressing this issue through a uniform 180-degree illumination design around the rodent’s tail, perched atop a flat base connected to a power source and equipped with a Broome style handler horizontally-positioned at the center of the structure. The illumination in laboratory rooms or the use of an ordinary desk lamp proves inadequate in discerning the rodent’s lateral veins as these lighting setups cause confusing reflections on the rodent’s tail.
Apparatus and Equipment
The light arc apparatus for tail injections consists of a rigid arc of 10 RGB LED bulbs, approximately one every 2 cm, standing on a flat base connected to a nearby power source. A Broome style handler is placed horizontally in the center of the structure, and it is where the subject is to be restrained.
The color contrast is regulated by the intensity of the primary colors and can be adjusted with red, green, and blue knobs for an optimal view of the veins. The accompanying Broome handlers, as well as the overall size of the light arc, may be varied depending on the rodent type.
Prior to metabolic cage utilization, rodents may first be typically housed in normal cages before being transferred to metabolic cages. Once individually-housed in metabolic cages, fecal pellets and urine are collected after a prescribed amount of time and immediately stored and refrigerated before analysis. The samples are weighed at the time of collection, whereas the subjects are weighed daily and after every sampling occasion (Eriksson et al., 2004).
The first step in intravenous injection procedures is determining the exact volume of drug substances to be administered, depending on the animal’s weight. The RGB light contrasts are then adjusted to meet the optimal contrast of the lateral caudal veins. Once the light arc setup is ready, the syringe is prepared and filled with the drug substance. Air bubbles must be removed. Importantly, the drug injection must be of moderate temperature, as administering large quantities of the cold solution may cause hypothermia and alter the efficacy of the drug under consideration.
Once everything is set, the rodent is then placed into the Broome handler. It is important to follow proper handling techniques when using restraint devices, as even minimal handling can cause considerable distress to the animal. (Refer to Broome handler’s protocol section for detailed instructions). Afterwards, the rodent’s tail is submerged in a warm water bath set at 42 degrees Celsius for an approximate duration of 40 to 45 seconds for vasodilation. A beaker must be placed in the water bath for urine and feces collection. Warming up the rodent’s body by using heat lamps may also be an efficient option, but takes longer and carries the risk of heat stroke.
The tail is afterward dried, and either of the lateral caudal veins is then located under the illumination of the light arc. Once a caudal vein is spotted, the tail is held with the thumb of one hand, and the needle is gently inserted with the dominant hand. The needle must be parallel to the vein and should not be penetrated more than 6 to 7 mm inside. The experimenter must not attempt to extract the blood back into the needle, as this may cause the vein to rupture.
The plunger must be pressed gently and slowly, and if the experimenter feels resistance or notices a lump, he/she must immediately stop, retract the needle, and re-insert it approximately 1 to 2 cm above the same vein. Once the injection is completed, the experimenter must cover the injection site with a swab before the needle is retracted to limit excess blood and drug loss. The swab must be kept pressed until the rodent is removed from the Broome handler. Afterward, if the restrainer is reused, it should be rinsed with a sufficient amount of water before it is replaced in the light arc structure for the next rodent injection.
Intravenous injections in transgenic mice and other experimental animals have been an integral development in biomedical and pharmacological research. These commonly involve the parenteral administration of large molecules, conveniently routed through the rodent’s lateral tail veins. The black strains of rodents present a challenge when it comes to making use of tail injections, with vein visibility a considerable concern due to poor vein contrast. The light arc apparatus is a necessity in providing sufficient and appropriate illumination to the rodent’s tail, resulting in successful I.V. injections. These intravenous procedures are commonly carried out in experiments that aim to examine and analyze different drug substances and their effects on animal behavior and physiology.
Strengths and Limitations
The light arc apparatus aids in delivering intravenous injections to black strains of rodents. The tool provides much-needed illumination, positioned in a 180-degree fashion so as to prevent reflection that would result from only one strong light source, and allowing the experimenter to adjust the color contrasts through RGB knobs.
- The light arc (Messer, 2015) is a novel device that aids in drug administration procedures by intravenous injections through the lateral tail veins of black strains of rodents
- The light arc apparatus for tail injections consists of a rigid arc of 10 RGB LED bulbs, approximately one every 2 cm, standing on a flat base connected to a nearby power source
- A Broome style handler is placed horizontally in the center of the structure, and it is where the subject is to be restrained
- The color contrast is regulated by the intensity of the primary colors and can be adjusted with red, green, and blue knobs for an optimal view of the veins. The accompanying Broome handlers, as well as the overall size of the light arc, may be varied depending on the rodent type.