SECOND EXPERIMENT AND MATHEMATIC CHANGES

Feb 02^nd 2012

Today Ms. Urban wasn’t in so I worked with Mr. Adams on another experiment. The previous one, my first experiment didn’t have good results; in fact, it didn’t work at all, no DNA was copied. So we’re to set up another one with some adjustments that Ms. Urban made to the “recipe”. This time we were to use 4 samples of DNA, the same ZAL group 13, 14, 15, and 16. The first experiment used ZAL 17, 74, 73, 76 and 75. We were also to use the same part of the DNA, NAD6. The Thermo cycler program however remained the same QIA42-57.

Before we began to make the master mix, Mr. Adams explained that they changed some of the recipe so that it matches the “original” experiment by some Brazilian researchers, he gave the published paper they wrote for me to get a better idea of what he was talking about.

The changes to the recipe was as follows:

PER 1 RXN	ORIGINAL AMMOUNT (microliters)	AMMOUNT IN STANDARD *4(microliters)	ALTERED (microliters) *4
Pure H2O	17.5	70	70
Buffer	2.5	10	10
MgCl2	1.5	6	(2.5)*4=10
dNTPs	2.0	8	8
Primers	.5	2	(.75)*4=3
Polymerase	.15	.6	(.2)*4=.8
TOTAL PER RXN		23		26.2
DNA		2		2

Unfortunately, Mr. Adams and I made a mistake and did not multiply the given amount by 4 to make the master mix and we ended up with very little mixture and could only distribute to 2 tubes. The total of the mix should’ve been about 386.4 microliters for the standard experiment and about 407.2 microliters for the altered mixture. Because there were 32 tubes, 16 for each group of experiment if we needed to multiply each amount to fit 16 tubes.

Even though we didn’t really make the mixture, I gained a bit more experience on how to use pipettes and it was great to make mistakes because it helps me learn and I can be more careful next time. We noted the mistake and next week we are to work on making the experiment correctly.