Development of Single Molecule Techniques for Sensing and Manipulation of CRISPR and Polymerase Enzymes.

Clustered regularly interspaced short palindromic repeats (CRISPR) and polymerases are powerful enzymes and their diverse applications in genomics, proteomics, and transcriptomics have revolutionized the biotechnology industry today. CRISPR has been widely adopted for genomic editing applications and Polymerases can efficiently amplify genomic transcripts via polymerase chain reaction (PCR). Further investigations into these enzymes can reveal specific details about their mechanisms that greatly expand their use.

Single-molecule Taq DNA polymerase dynamics.

Taq DNA polymerase functions at elevated temperatures with fast conformational dynamics-regimes previously inaccessible to mechanistic, single-molecule studies. Here, single-walled carbon nanotube transistors recorded the motions of Taq molecules processing matched or mismatched template-deoxynucleotide triphosphate pairs from 22° to 85°C. By using four enzyme orientations, the whole-enzyme closures of nucleotide incorporations were distinguished from more rapid, 20-μs closures of Taq's fingers domain testing complementarity and orientation.

Effects of different calcium sources on iron absorption in postmenopausal women.

We measured the effect of calcium from food and supplement sources on whole-body retention of 59Fe in 19 normal postmenopausal women. Each woman received a placebo and 500 mg calcium from a mixed calcium citrate-malate salt (CCM), from orange juice plus CCM, and from milk after a test breakfast meal to which 59Fe had been added. The test meal contained 238 mg calcium.

A nonparametric method for evaluating results from laboratory antinociceptive tests.

A method is presented in which Cox's proportional hazards model, a survival analysis technique, is used to assess the results of hot-plate antinociceptive testing. The method appropriately handles censored data values and variable pretest latency times without making arbitrary assumptions about the distribution of the data. It may be used to characterize and compare dose-response curves or to examine the effect of agent or other treatment variables on the response.