Week 1 Lab: Pipetting

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Dillution Practice 2

Answer:

  1. MS Concentration: 5M Molar mass: 532 g/mol How many stocl concentration in g/mL? Answer: 5M equal to 5 mol/L —–> 5M mol (gr/molar mass)/Liter 5M= gr/532 gr per mol / 1000 mL

Result: mass = 2.66 gr

  1. I use P1000, P200, P20 pipette with eppendorf tube for serial dillution. Dillut solution: dH2O. Breakdown into 3 steps:

    • Step 1 (1: 100): Take 10 uL stock 5 MS solution + add 990 uL dH2O. Concentration from 5M —-> to 50 mM
    • Step 2 (1:100): Take 10 uL stock 50 mM solution and then add 990 uL dH2O into eppendorf tube. Concentration from 50 mM —-> to 0.5 mM
    • Step 3 (1:5): Take 200 uL stock 0.5 mM and then add 800 uL dH2O into eppendorf tube. Concentration from 0.5 mM —-> to 0.1 mM

  2. It is easire to prepare 100 µM stock solution because more reproducible and more accurate if we want to dillute it into smaller concentration. If we dillute it directly into 40 µM from higher stock Conc. it often requires very small volume, which increasing uncertainty of measurement.

    • Table volume: Loading dye 10 µL ; MS 24 µL ; dH2O 26 µL. Total volume 60 µL