PCR has found immediate use in developmental DNA diagnostics procedures and in molecular cloning from genomic DNA. (1~ Current protocols for PCR amplification require the dispensing and mixing of aqueous solutions stored at subambient temperatures. In addition, dispensing of such aqueous reagents involving enzymes, buffers, and nucleotides is time consuming. It also may lead to pipetting errors as well as an increased probability of carry over contamination of pristine PCR mixtures. Having

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... dered the need for rapid testing and automation, we have developed an alternate approach to stabilizing PCR reaction mixtures in carbohydrate polymers. This process leads to the formation of glassy matrices that provide room-temperature stability (referred to as stabilized): This paper describes the utility of stabilized PCR reagents and subsets of PCR reagents containing buffered Taq DNA polymerase and/or nucleotides for routine PCR applications. RESULTS AND DISCUSSION The PCR reagent mixture, containing 2.5 units of Taq DNA polymerase (Perkin Elmer Cetus), 0.2 mM each of dNTPs (Pharmacia), and I x standard PCR reaction buffer [10 mM Tris-HC1 (pH 8.3), 50 mM KC1, 1.5 mM MgC12, 0.001% gelatin (Perkin Elmer Cetus)], was mixed with an equal volume of 20% (wt/vol) carbohydrate polymer and processed to form a stable, glassy matrix. (2) The stabilized PCR mixtures were stored at room temperature for extended periods of time and tested in PCR. Figure 1 shows the amplification of a pBR322 DNA template utilizing PCR reagents prepared from aqueous solutions (stored at -20°C) and stabilized reagents (stored at room temperature for 11 months). The stabilized reagent mixture was rehydrated with 100 t~l of water containing the specific primers and DNA template. Equivalent amounts of PCR product were observed with fresh reagents and stabilized reagents ( Fig.