Search

  • 联系我们
  • 货号直购

PrepMan™ Ultra Sample Preparation Reagent, with protocol - FAQs

查看更多产品信息 PrepMan™ Ultra Sample Preparation Reagent, with protocol - FAQs (4322547)

5 个常见问题解答

Is there any way to remove PCR inhibitors that may be present even after pre-enrichment of samples for pathogen detection?

There are three optional steps of removing PCR inhibitors after the pre-enrichment step with PrepMan Ultra Sample Preparation Reagent (P/N 4318930): Serially diluting the sample, Precipitating the nucleic acids, or Performing Spin Column Purification. These optional steps may be necessary for specific samples such as coca, juice precipitates, or spices that contain potent PCR inhibitors. For more information, please consult pages 15 -17 of the PrepMan Ultra Sample Prep Reagent Protocol.

Where is the DNA layer after using the PrepMan Ultra Sample Preparation Reagent (P/N 4318930)?

After the final step of centrifugation, the DNA is in the supernatant. The supernatant should not be discarded. The pellet contains protein and other cellular components that are digested during the 10 minute incubation of the lysate at 100 deg C. For more information please refer to the PrepMan Ultra Sample Prep Reagent Protocol.

Why is it important to dilute the final supernatant when using PrepMan Ultra Sample Preparation Reagent?

The final supernatant must be diluted at least 1:10 to minimize the amount of potential inhibitors from the sample and from the PrepMan Ultra Sample Preparation Reagent (P/N 4318930). In some cases, highly concentrated cultures (at about 10E8 cfu/ml or more) or residual PrepMan Ultra reagent can form gel-like masses that may inhibit PCR.

What is the purpose of performing pre-enrichment on food samples for isolation of DNA with PrepMan Ultra reagents?

Without performing any specific pre-enrichment step on certain food samples like meat, the use of the PrepMan Ultra Sample Preparation Reagent (P/N 4318930) will not enable the reduction of many forms of PCR inhibitors such as fats, tissues and particulates. Thus, pre-enrichment significantly reduces the detection of false positive signal from dead or nonpathogenic cells in food samples. Improper pre-enrichment steps can hamper the process of extracting DNA of the highest purity and affect the performance of TaqMan Pathogen Detections kits for Salmonella enterica, Listeria monocytogenes, Campylobacter jejuni, E. coli 0157:H7, or MicroSeq kits.

When using the PrepMan Ultra kit (P/N 4322547), can the cell pellet be stored in the PrepMan Ultra reagent for an extended period of time (i.e. 24 hours)?

We do not recommend storing the cell pellets in the PrepMan Ultra reagent. Once it is added, the samples should be processed. After the PrepMan Ultra reagent has been added to the cell pellet, the mixture should be promptly vortexed for 10 seconds and then immersed in 100 C water for 10 minutes. Please refer to the Ultra Sample Prep Protocol or the PrepMan Ultra Sample Prep Quick Reference Card for more information on the procedure.