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Does milk have any cow genes?

Series: Brief measurement

Does milk have any cow genes?

Milk is nutritious and reasonable. There are a lot of types of milk products including low-fat milk, processed milk, and dairy products. Is the difference measurable?
Testing the difference is important for people with allergies.
Measuring milk is very interesting because milk is very familiar to our life. We first checked if milk has any cow genes using a mobile PCR device.

Reaction composition
μL Remarks (final concentration)
Enzyme: KAPA 3G Plant (2.5 U/μL) 0.6 1.5U/reaction
Buffer (×2) 8 x1
F-Primer: cow (100 μM) 0.06 400nM
R-Primer: cow (100 μM) 0.13 800nM
Probe: cow (100 μM) 0.03 200nM
MgCl2(25mM) 0.8 1.25mM
Sample 1
PCR grade water 5.4

Reaction sample total 16μL

Process Temperature Time
Initial denaturation 95℃ 15sec
Annealing/extension 63℃ 15sec 50cycle
Denaturation 95℃ 3.5sec

Cow genes were present in an amount that the sensor easily reacted even when it was diluted 100 fold.
This indicates that the presence of milk residue can be measured via PCR.

*1 Primer/probe sequence
Cow-Primer F    5′-CCCGATTCTTCGCTTTCCAT-3′ (20mer) 66.8
Cow-Primer R    5’-CTACGTCTGAGGAAATTCCTGTTG-3′ (24mer) 65.4
Cow-probe         5’FAM-CATCATAGCAATTGCCATAGTCCAC-3’BHQ1 (25mer) 72.9

Made by Nihon Gene Research Laboratories Inc.
Tm values are calculated using the nearest neighbor method. However, the calculation method of Nihon Gene Research Laboratories was used for the probes.
Reference paper:Tanabe et al., A Real-Time Quantitative PCR Detection Method for Pork, Chicken, Beef, Mutton, Horseflesh in Foods.
Biosci. Biotechnol. Biochem., 2007, 71(12),3131-3135