Size agarose gels

FIG. 9 Polyacrylamide and agarose size distribution, (a) Agar gels, (b) polyacrylamide gels, and (c) agarose gels. (Reprinted with permission from Ref. 79, Copyright 1995, Academic Press.)... 

Agarose gel electrophoresis can be used to determine whether the PCR amplicon is the expected size. The density of the gel should be chosen to ensure resolution of... 

Visualize the PCR product on agarose gel to confirm correct size of a single product and analyze melting curve to further confirm only one product was amplified. 

The in vitro transcribed RNAs are phenol-chloroform extracted, ethanol-precipitated, and washed once with 70% ethanol. The RNA pellet is resuspended in 30 1 H20 and loaded to DyeEx 2.0 spin columns (Qiagen) to remove free nucleotides the RNA is then quantified by spectrophotometry. Approximately 20 to 30 pg of RNA is obtained from one reaction. For the initial preparation of transcripts, we would examine the quality and quantity of synthesized RNA by separating them on 1% denaturing agarose gels with total cell RNA preparation as a size maker (28S and 18S ribosomal RNAs... 

Prepare 1.2 to 2.5% agarose gel (depending on the expected sizes of fragments) in 1 X MOPS and formaldehyde (1.3% final concentration). Dissolve the agarose first in water, let cool to 65°, and then add the lOx MOPS and formaldehyde. 

A RESTRICTION MAP is used to identify and locate specific restriction sites on a given piece of DNA. The size of a fragment is determined by running the restriction digest on an agarose gel. Fragments separate by size—the smaller ones move farther toward the bottom of the gel. 

Agarose gel electrophoresis can only be used for DNA molecules that are greater than 200 base pairs in size. For molecules smaller than this polyacrylamide gel... 

Electroimmunoassay (rocket electrophoresis) and radial immunodiffusion (A5) lack sensitivity at low Lp(a) concentrations, and the response is influenced by the size of the apo(a) isoforms (A5, K28). Differences in migration velocity in the agarose gel lead to an underestimation of the samples with large apo(a) isoforms and to an overestimation of samples with small apo(a) isoforms. Moreover, the detection limit lies around 0.07-0.08 g/liter Lp(a), so that this method is better suited for screening and detection of individuals with elevated Lp(a) levels than for the exact measurement of the plasma Lp(a) concentration. 

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