A polarized photobleaching study of DNA reorientation in agarose gels

Journal Article · Tue May 22 00:00:00 EDT 1990 · Biochemistry; (United States)

DOI:https://doi.org/10.1021/bi00472a007· OSTI ID:5324041

Scalettar, B A; Klein, M P ^[1]; Selvin, P R; Hearst, J E ^[2]; Axelrod, D ^[3]

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1. Lawrence Berkeley Laboratory, CA (USA)
2. Lawrence Berkeley Laboratory, CA (USA) Univ. of California, Berkeley (USA)
3. Univ. of Michigan, Ann Arbor (USA)

Polarized fluorescence recovery after photobleaching (pFRAP) has been used to study the internal dynamics of relatively long DNA molecules embedded in gels that range in concentration from 1% to 5% agarose. The data indicate that, even in very congested gels, rapid internal relaxation of DNA is largely unhindered; however, interactions with gel matrices apparently do perturb the larger amplitude, more slowly (microseconds to milliseconds) relaxing internal motions of large DNAs. The relationship between this work and recent studies which indicate that internal motions of DNA play an important role in the separation achieved with pulsed-field gel electrophoresis techniques is discussed. The polarized photobleaching technique is also analyzed in some detail. In particular, it is shown that reversible photobleaching phenomena are probably related to depletion of the ground state by intersystem crossing to the triplet state.

• OSTI ID: 5324041
• Journal Information: Biochemistry; (United States), Vol. 29:20; ISSN 0006-2960
• Country of Publication: United States
• Language: English

Related Subjects

59 BASIC BIOLOGICAL SCIENCES
DNA
ELECTROPHORESIS
ANISOTROPY
FLUORESCENCE
POLARIZATION
ROTATIONAL STATES
ENERGY LEVELS
EXCITED STATES
LUMINESCENCE
NUCLEIC ACIDS
ORGANIC COMPOUNDS
550200* - Biochemistry