Serological Pipets Blue Pump 2mL, Green Pump 10mL , Red Pump 25 mL Never ever mouth pipet Solutions should never touch the cotton plug Pipetting should always be done at eye level Pipet always be in a vertical position Numbers represent how much you have pipetted Example if I fill the pipet to the 0 line and pipet 1mL the meniscus will touch the 1 mL line *** Pipets on Practical will only have the reverse numbers

Serological Pipets Without Touching the pipet tip, remove it from the plastics sleeve Insert the wide end into the pipet pump Twist the pipet gently into the pump to get a tight seal Fill the pipet a bit above the amount desired and then slowly lower the meniscus to that line. Remove the pipet and discard it into an appropriate discard container.   Pipet can be reused for same solution only!!!!

Serological Pipet Basics

Lab 3A Measuring small volumes Solutions add across the data tables You must uses the different color dyes to get the final solution You will compare your final solution to mine and it should be the same volume and roughly the same color. Red Blue Green Yellow Purple

Using a Micropipette

Choosing and Setting a Micropipette Choose the smallest pipet that can measure your volume Set the pipet Numbers get larger when you move the dial to the right Numbers get smaller when you move the dial to the left

Setting Micropipet Practice For each of the following-Draw the correct setting!!! P20 set to 15.85 P100 set to 56.5 P1000 set to 265 P200 set to 19.5 P20 set to 3.5

Using a Centrifuge TAB Put the tubes opposite each other in the centrifuge. Tubes should be loaded with tab facing the inside Make a counterbalance for the centrifuge tube you want to put in the centrifuge. The masses, not volumes, of the tubes should be as close as possible! Unbalanced tubes may permanently damage the centrifuge If balanced it will be almost silent

Using a Centrifuge Close the lid, will turn on if balanced Do not open the lid until it stops spinning completely Remove the tubes carefully after the centrifuge so they don’t get mixed up again Most often used to separate suspensions in liquids. Also used to mix small amounts of liquid and relocate to bottom of tube.

Using a Centrifuge

During the Practical You Should One set of solutions per Lab Station (17 tubes) ALL solutions must be done by the end of class 11/7. Prelab for 3E (M/V) and 3F (%/M/V) Do not do the actual Biuret testing until the lab on 11/16 Prelab for 3H (C1V1=C2V2) Make all solutions for 3E, 3F and 3H Calculations only for 3G (Molarity) Don’t forget TLABS (review Sheets)

Using a GLX Using a Colorimeter Remember Copper Sulfate and Heavy medals must go in the waste container in the hood

Background on spectrophotometer

A spectrophotometer is a device used to measure light at a specific wavelength. It consists of two parts: a spectrometer and a photometer. The spectrometer provides light at a specific wavelength. The photometer measures how intense the light is. By calculating the amount of light that a solution is able to absorb and applying Beer's Law, the spectrophotometer can determine the concentration of a colored solution.

Spectrophotometer video https://www.youtube.com/watch?v=LL36zKV 12zs