Investigator Casework GO! Kit

For the direct amplification of casework samples, including:

Features

•        Lysis of forensic casework samples for subsequent use in direct amp workflows

•        Maximize of the chances of recovering DNA from a variety of trace samples

•        Enable Y-screening and selection of evidentiary samples for STR testing

Investigator Casework GO! Kit

Cat. No. / ID: 386546

Casework GO Lysis Buffer, Proteinase K Solution, and Nuclease-Free Water
KitAccessories
Casework GO! Kit
DTT
The Investigator Casework GO! Kit is intended for molecular biology applications in forensic, human identity and paternity testing. This product is not intended for diagnosis, prevention or treatment of a disease.

Product Details

The Investigator Casework GO! Kit can be used to perform lysis of forensic samples on a variety of substrates, including sexual assault swabs, pieces of fabric, paper, cigarette butts, chewing gum and other sample types. The generated lysates are compatible with all Investigator Quantiplex and Investigator STR QS Systems.

Principle

The Investigator Casework GO! Kit is used for the pretreatment of forensic samples in a direct amplification workflow. The kit permits sample lysis without DNA purification and the lysate is compatible with several downstream options, including the Investigator Quantiplex Pro and Quantiplex Pro RGQ or the Investigator 24plex QS, ESSplex SE QS or IDplex Plus Kits.


The Investigator Casework GO! Kit can be used for direct amplification of casework samples and thus enables an accelerated workflow in casework analysis. It allows the rapid processing of swabs from casework samples, including cuttings of sexual assault swabs, or other materials, without the need for further purification. The lysate can be used directly for quantification with all Investigator Quantiplex assays or for DNA profiling using all Investigator STR assays (unless data from the quantification indicates presence of possible PCR inhibitors).


In sexual assault screening analyses, the Investigator Casework GO! workflow can facilitate sample processing decisions by male-quantification and Auto/Y ratio.

Procedure

Add 100–400µl of Casework GO! Master Mix to the sample in a tube and incubate at 60°C for 25 minutes followed by an additional 5 minutes at 80°C. Quantify 2–5 µl of this lysate using the Quantiplex Pro kit and use up to 15µl of the lysate for amplification using the Investigator STR QS Kit.

Applications

Casework Samples

Many high-volume crime samples (e.g., from burglaries or vehicle-related crimes) go untested because there is no funding or time available for sample prep. With Investigator Casework GO! Kit, one can remove the sample prep step which makes the generation of DNA profiles faster and cheaper and could make DNA testing more viable for a greater number of high-volume crime samples. Valuable workflow information, such as the presence/absence of male/total human DNA, sample degradation or the presence of potential PCR inhibitors, can be obtained when the Investigator Casework GO! Kit is used with the Quantiplex Pro Kits or Investigator STR QS Kits.


Sexual Assault Evidence/Y-screening

Many sexual assault cases lie in storage for months or even years because the effort and complexity of recovering PCR-ready DNA is too great. The use of a “Direct to DNA” approach, in line with the latest SWGDAM recommendations, maximizes the chances that only samples worth processing fully are pursued further. The Investigator Casework GO! Quantiplex Pro-workflow determines the male/female DNA ratio and predicts PCR inhibition as well as sample degradation. It thus provides a rapid Y-screening and quality assessment for selection of evidentiary samples for further STR testing.

Resources

Quick-Start Protocols (1)
Validation Reports (1)
Additional Resources (1)
Application Notes (2)
Application Note Investigator Casework GO!  Kit
Application Note Skin flake isolation with the Investigator Casework GO! Kit

FAQ

Why is DTT used only for semen samples?
The DTT breaks down the protein disulfide bridges that make up the sperm nuclear membranes. Thus, DTT is always required for semen lysis.

It may also be used for all samples to keep the process simple, but it is not required to lyse blood, epithelial cells, etc. 
FAQ ID - 143761
Is it possible to use Lyse&Spin baskets?
It is possible, but modifications to the heat incubation is required because the temperature transfer to the sample might decrease due to the two plastic walls of the vessel.

This could reduce the yield and ProtK inactivation efficiency.

Note: ProtK inactivation must be done after sample collection and removal of the basket.
FAQ ID - 143762
How long are sample lysates stable in the fridge/ freezer?
In the fridge, at least 1 week.

In the freezer, minimum of 4 weeks.




FAQ ID - 143765
How critical is the time of the temperature change from 60°C to 80°C?
There is no adverse effect for samples remaining in the heater during temperature increase. Nor does it make a difference if samples are kept on the bench until the heater has reached its temperature.

If only one heater shaker is available, the protocol will take a few minutes longer than the usual processing time.
FAQ ID - 143768
If 400 µl are used as lysis volume, how do I concentrate the lysate? (Otherwise the DNA would be too diluted.)
Different concentration devices are available on the market, but are not tested with the kit. Testing needs to be done first by customer.

Another helpful modification is the starting lysis volume, which can be reduced for most of the swab type to 200 µl. This helps to have higher sample concentrations.




FAQ ID - 143766
What if only one heater shaker is available?
The usage of only one heater shaker does not adversely affect the outcome.

The process will just last a few minutes longer than the usual processing time.
FAQ ID - 143764
Can the lysis volume be reduced for higher sensitivity?
The ideal lysis volume needs to be determined for each collection device.

For cotton swabs (e.g. Sarstedt Forensic swabs), 200 µl are usually sufficient.

Cuttings can be lysed with 100 µl Casework Go! Buffer depending on the size.
FAQ ID - 143763
Why is there no male DNA obtained from sexual assault samples?
DTT is not stable. The 1M solution should be stored frozen in small aliquots (50 µl) and disposed after thawing.

Repeat with freshly made DTT solution.
FAQ ID - 143767