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a lab assistant needs to mix up the following reaction to prepare dna for an experiment:
25ul of a dna sample
25ul of enzyme
50ul of reaction buffer
400ul of water
the smallest size tube that will hold the entire reaction is [0.05, 0.5, or 5] ml:
which of the following pipetting devices most likely would not be used by the lab assistant to measure the needed volumes? ? [p20, p200, p1000]?
the enzyme comes as a concentrated solution of 20 units of activity per ul. therefore, the reaction mix will have total units of the enzyme at a working dilution of units/ul.

The smallest size tube that will hold the entire reaction is 0.5ml

Explanation:

25ul (DNA sample) + 25ul (enzyme) + 50ul (buffer) + 400ul (water) = 500ul total

since 1000ul=1ml, then 500ul = 0.5ml

The device that mostlikely would not be used P20

Explanation:

P20 is a pipette used to measure and sample volumes of 20ul maximum.

The reaction mix will have 400 units of the enzyme.

The working dilution will be 0.8 Units/ul.

Explanation:

The mix has 20ul of the enzyme which is 20Units/ul. Then we have 20ulx20Units/ul= 400 Units of enzyme in the mix.

Since the final volume is 500ul, the final concentration 400Units/500ul=0.8 Units/ul.

answer : haversian

[explanation: -(compact bone is organized as parallel columns, known as haversian systems, which run lengthwise down the axis of long bones. these columns are composed of lamellae, concentric rings of bone, surrounding a central channel, or haversian canal, that contains the nerves, blood vessels, and lymphatic system of the bone)]