Question21 Complete the following statement by selecting the most correct answer from the options below. When practicing accurate pipetting techniques: Select one alternative: pushing the plunger all the way down to the second stop allows the complete volume of liquid to be expelled from the tip. changing tips between different solutions to be transferred is not necessary. holding the pipette at an angle (between horizontal and vertical) permits the solution to be drawn up more accurately. placing the end of the tip further down into the liquid when drawing up the solution to be transferred allows more effective mixing. the smallest volume you can accurately pipette is approximately 1% of the maximum volume. ResetMaximum marks: 1 Flag question undefined

Question

BlackTom AI · Accepted Answer

Question: Complete the following statement by selecting the most correct answer from the options below. When practicing accurate pipetting techniques: Select one alternative.

Option 1: pushing the plunger all the way down to the second stop allows the complete volume of liquid to be expelled from the tip. This is correct because on most adjustable micropipettes, the second stop is designed to expel all residual liquid from the tip, ensuring accurate delivery of the set volume.

Option 2: changing tips between different solutions to be transferred is not necessary. This is false because cross-contamination can occur if tips are reused between different solutions; standard practice requires changing tips for each separate transfer.

Option 3: holding the pipette at an angle (between horizontal and vertical) permits the solution to be drawn up more accurately. This is inaccurate because drawing up liquid is best done with the pipette held upright (near-vertical) to prevent air intake and to maintain volume accuracy; tilting reduces accuracy.

Option 4: placing the end of the tip further down into the liquid when drawing up the solution to be transferred allows more effective mixing. This is misleading: lowering the tip into the liquid can cause aspiration of more liquid than intended, introduce air bubbles, or cause inconsistent volumes; proper mixing is achieved by gentle resuspension or pipette operation, not by deeper tip placement.

Option 5: the smallest volume you can accurately pipette is approximately 1% of the maximum volume. This statement is not universally true; the reliable accuracy depends on the specific pipette model and calibration, and many models have best accuracy in a defined range, not a fixed 1% of max for all cases.

In summary, option 1 accurately reflects the correct use of the second stop to expel all of the liquid from the tip, while the other options describe practices that would compromise accuracy, safety, or cross-contamination control in pipetting.

类似问题

使用移液器吸取液体时，活塞应该按压到哪个位置？

用移液器吸取液体时，活塞应该按压到哪个位置？

When loading an pipetter with liquid, to which stop do you depress the plunger?

When dispensing liquid from an autopipette, to which stop do you depress the plunger?

Which of the following actions are recommended when releasing fluid from the pipette tip into a container?

Which of the following actions are recommended when releasing fluid from the pipette tip into a container? 在将液体从移液器尖端释放到容器时，推荐以下哪些操作？

Which of the following actions would ensure that a micropipette delivers an accurate and reliable volume of liquid?Note: the term “aspiration/aspirating” in this context refers to the process of bringing a solution into the micropipette.

For standard aspiration, press the plunger to the [ Select ] first second third stop. For dispensing, press to the [ Select ] first second third stop to dispense the bulk of the liquid, then continue to the [ Select ] second first third stop to blow out any remaining droplets.

更多留学生实用工具

智能学习助手

风格化写作助手

论文查重助手

文献引用助手

课堂转译助手

课堂笔记助手

Quiz搜索助手

学校历年真题

智能刷题助手

智能匹配练习

希望你的学习变得更简单