A fundamental aim within this lab section involves assessing the P200 and P1000 micropipette’s relative precisions as well as accuracies by gauging water volumes that are already known. Such foundational skills become paramount across different fields of study where reliability forms part and parcel concerning obtaining credible scientific results.
In order to precisely transfer small liquid volumes within laboratory settings, the experimental procedure required students to become proficient in using micropipettes. The study utilized two distinct types of micropipettes: the P200 (capable of handling 20-200 μL) and the P1000 (with a range between 100-1000 μL).
In order to evaluate both precision and accuracy, every student executed three trials employing micropipettes, which were used for measuring specific volumes of distilled water. The protocol was standardized in the following manner: Initially, the appropriate volume required was set on the micropipette using a volume adjustment knob. Subsequently, depressing a plunger until it reached its first softer stop position came next; upon reaching this position, an expendable tip needed to be connected. After completing that step successfully, the micro-pipette could now be slightly immersed in liquid while being released slowly by drawing up any amount left therein by retracting from within the dispenser’s first stage limit. Finally, the resulting pipette tip should disengage gently against any accepting target surface before again being depressed using the force provided, reaching full plug clearance–which happened at the second phase but only after one has waited patiently enough For a Second Stop After A One-Second Interval. Well, this whole process culminated fittingly as soon after that, the ejector button brought out detachable tips, too!
Menze et al. (2015)devised a meticulous process that enabled learners to hone their micropipetting skills and gather information for future evaluation of the precision and accuracy of micropipette measurements.
Table 1 displays the findings obtained from micro pipetting experiments that employed P200 and P1000 micropipettes. The students performed three sets of trials with each pipette to calculate different quantities of water, resulting in valuable observations related to both precision and accuracy.
| Student | P200 Trial 1 (μL) | P200 Trial 2 (μL) | P200 Trial 3 (μL) | P1000 Trial 1 (μL) | P1000 Trial 2 (μL) | P1000 Trial 3 (μL) |
| Anabelle | 145 | 144 | 148 | 484 | 494 | 488 |
| Parth | 097 | 094 | 096 | 485 | 489 | 485 |
| Antka | 496 | 493 | 495 | 105 | 097 | 098 |
| Rae | 099 | 097 | 098 | 462 | 493 | 482 |
| Maha | 094 | 099 | 094 | 491 | 493 | 496 |
| Mark | 097 | 097 | 097 | N/A | N/A | N/A |
| Average | 129.5 | 129.8 | 131.3 | 449.5 | 464.0 | 464.8 |
Micropipetting accuracy pertains to the proximity of measured volumes to intended ones. In our trial, 100 μL was designated as the planned volume for P200 and P1000 micropipettes. Nonetheless, findings showed a steady overestimation in delivered volumes by these pipettes – with an average recorded value close to 129.5 μL for P200 and around 449.5 μL for P1000, respectively(thus indicating positive bias). These observations imply that said devices constantly dispensed higher-than-intended measures(typically set at precisely or near-to exactly) of approximately 100μl each time they were utilized during experiments.
Precision refers to the consistency and reproducibility of measurements. The standard deviation was computed for each trial in order to determine precision. Results indicated good measurement precision for P200 trials, as evidenced by relatively low standard deviations (Singer et al., 2016). Likewise, consistent and replicable results were found in P1000 tr
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