{'fraction_non_alphanumeric': 0.020869565217391306, 'fraction_numerical': 0.0026086956521739132, 'mean_word_length': 4.5603864734299515, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Simple and rapid 5' and 3' extension techniques in RT-PCR.

We describe a procedure for successively extending or walking along cDNA clones beyond a known sequence. In order to obtain sequences 5' to the constant a domain sequence (C a) of the human T cell receptor (TCR), we routinely used a nested primer set for RT-PCR. The unusual feature of the procedure described here is the use of a single spurious primer as one of two primers in the first and subsequent PCR reactions. This allows the use of previously available primers. We have demonstrated it to be effective for a wide range of primer sequences. The first PCR amplification is inefficient but in the second round the nested primer in the TCR-C ca region allows specific exponential amplification of the desired sequence. We used the method routinely to isolate variable a (V a) segments for sequencing and subsequent cloning into expression vectors. Using three parallel reactions for each cDNA sample with different arbitrarily chosen spurious primers we have been able to isolate and determine the V a and joining a (J ax) sequences of all of the ten human T cell clones investigated.