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# chandch

Member Since 28 Aug 2012
Offline Last Active Apr 15 2013 06:48 AM

### Calculating PPM

11 December 2012 - 10:33 AM

Hi all
I am trying to calculate 1 ppm, 100 pmm for cis-3- hexenyl acetate solution (98%). FW is 142.2 and density is 0.897. Can anybody help me how to calculate ppm.

Thank you

### Bradford assay Standard Curve Calculation

06 December 2012 - 01:18 PM

Hi all

1) BSA Stock 1mg/ml dissolved in deionised water 2) Bradford reagent from Sigma

I took 5µl of stock BSA and add 995µl of Bradford reagent and checked 0.D at 595 nm and also took 10µl, 25µl, 30µl, 40µl, 50µl, 60µl, 70µl of stock BSA and add 990, 975, 970, 960, 950, 940, 930 µl of Bradford reagent and did O.D at 595 nm.

BSA  (1mg/ml)   Bradford reagent    0.D 595
5  µl 995  µl   0.106
10 µl 990 µl 0.236
25 µl 975 µl    0.544
30 µl 970 µl    0.690
40 µl 960 µl    0.791
50 µl 950 µl    0.861
60 µl 940 µl   0.882
70 µl 930 µl    0.911

The value I got from the graph was

y = 16.04x

R² = 0.7773

Now I have my protein sample (unknown concentration), I did in the following way.

Protein Sample 1    Bradford 0.D 595

10µl   990 µl   0.117
40 µl 960  µl 0.726
50 µl 940 µl   0.813

Protein Sample 2    Bradford   O.D 595
10 µl    990 µl    0.135
40 µl    960 µl    0.545
50 µl    940 µl    0.821

Protein Sample 3   Bradford 0.D 595
10 µl    990 µl 0.05
40 µl    960 µl 0.321
50 µl    940 µl 0.671

Then I did calculation in this way:  Y = 16.04 x
x= y/16.04 and I got 0.958 mg/ml for sample 1, for sample 2 I got 0.904 mg/ml and for sample 3 I got 0.516 mg/ml

Now I need up to 350 µl for gels, but I need same concentration, so I took the lowest one which is sample 3 (516 µg in 1000 µl) so in 350 µl I got 180.6 µg.

Then I calculated for sample 1 (958µg in 1000 µl) so I got 180 µl and for sample 2 (904 µg in 1000 µl), so I got 199.7 µl

Is this the right way I did to check the known concentration and required concentration? Please help

### Molar calculation from liquid

30 November 2012 - 10:33 AM

Hi all
I am trying to calculate 0.1mM, 10mM, 1mM and 1M concentration. The molecular weight is 90.12 (It is in liquid form and 99% pure). How do I bring down to the required concentration, if I need 5ml each.

Regards
Chandch

### Calculation Bacteria

15 November 2012 - 09:35 AM

Hi
I am trying to calculate colony forming units calculation. I cultured bacteria overnight (15ml) and did O.D reading at 0.4 and did serial dilution (10*1 to 10*9) and I got 55 colonies at 10*4 dilution. So I got 5.5 × 10*6 cfu/ml (original, if I am right).  But I need 1 ×10*7 CFU/ml (for my experiment). How can I Increase it it. Please give example calculation.

2) I also cultured bacteria overnight (15ml) and did O.D reading at 0.4 and did serial dilution (10*1 to 10*9) and I got 85 colonies at 10*5 dilution. So I got 8.5 × 10*7 cfu/ml (original, if I am right).  But I need 1 ×10*7 CFU/ml (for my experiment). How I can I reduce it down?

Thank you

### 10 millimolar (mM) to 250 micromolar

28 August 2012 - 11:34 AM

Hi
I am trying to calculate colony forming units calculation. I cultured bacteria overnight (20ml) and did O.D reading at 0.4 and did serial dilution (10*1 to 10*9) and I got 250 colonies at 10*6 dilution. So I got 2.5 × 10*9 cfu/ml (original, if I am right).  But I need 10*6 or 10*7 CFU/ml (for my experiment). How can I reduce it down to it. Please give example calculation.

Thank you